JP5377091B2 - Information processing apparatus and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a proxy response during a power-saving mode, even in a connection-type communication protocol or a protocol performing session setup processing. <P>SOLUTION: An information processing apparatus includes a main system for executing a communication application and a sub system for performing connection-type communication with an external device, under the control of the main system and operates while switching a normal mode where the main system performs control of the communication and a power-saving mode, where the main system does not perform control of the communication. In the information processing apparatus, the communication application executes shifting to the power-saving mode during waiting for reception of a packet by using a set-up connection, and according to the shifting to the power-saving mode, the sub-system executes proxy response processing, while the connection waiting for the reception of the packet is maintained. When the system is to return to normal mode, communication application is made to continue the communication by using the connection maintained in the sub-system. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an information processing apparatus and a control method thereof. In particular, the present invention relates to an information processing apparatus that communicates with other apparatuses connected to a network, and a power saving mode control method in the information processing apparatus.

  In recent years, low power consumption is required for various products. For this reason, in order to reduce power consumption during standby, apart from the normal mode in which normal application processing is performed, devices having a power saving mode in which power consumption is reduced during standby are increasing.

  On the other hand, in a device connected to the network, a request is periodically generated via the network. For example, in printers and copiers shared over a network, status confirmation requests are frequently issued from each terminal using a protocol such as SNMP (Simple Network Management Protocol). Therefore, every time such a request is received, if the mode is returned from the power saving mode to the normal mode, the normal mode is frequently set, and thus the effect of reducing power consumption is reduced.

  Therefore, a proxy response that returns a response to a request from another terminal by turning off the power of the part other than the communication unit and turning on only the communication unit in the power saving mode is known. In the proxy response, when a response can be returned only by the communication unit with respect to a request transmitted from another terminal in the power saving mode, the communication unit returns a response while turning off the power of the part other than the communication unit. If processing cannot be performed only by the communication unit, the normal mode is restored and the request is responded.

  As a conventional technique of proxy response, there is a proxy response in a network device including a main CPU that controls processing of the entire device and a sub CPU for communication processing (Patent Documents 1 and 2). In these conventional techniques, in response to a request via the network, the main CPU performs processing and returns a response in the normal mode. On the other hand, in the power saving mode, the main CPU is turned off, the sub CPU performs processing, and returns a response on behalf of the main. As a result, it is possible to respond to a request via the network in the power saving mode in which the main CPU is turned off, so that power consumption can be reduced.

JP 2003-089254 A JP 2006-259906 A

  In the prior art, a proxy response is made only to a connectionless communication protocol such as SNMP or ARP (Address Resolution Protocol), and the connection type protocol is not supported. For example, in a TCP-based connection type protocol, information related to the connection is lost in the power saving mode, and communication cannot be performed. Some communication protocols perform session establishment processing such as user authentication and communication protocol version negotiation between terminals before actual data communication. In the prior art, a proxy response could not be made to a protocol for establishing such a session.

  Even in such a TCP-based connection-type protocol or a protocol for performing session establishment processing, a status confirmation request is periodically generated. An example of this is the SMB (Server Message Block) protocol. Many multifunction peripherals and the like have a storage such as a memory card, and these storages are generally shared by a TCP-based connection-type communication protocol such as the SMB protocol. In SMB, a request for confirming the state of a device providing a shared resource is issued periodically. If the request cannot be responded, it is determined that the status confirmation source terminal is no longer on the network. For this reason, there is a problem that the storage shared by the SMB cannot be seen from the PC, or even if the storage is accessed from the PC, the multifunction device does not return a response and an error occurs. Further, a problem occurs not only when the normal mode is shifted to the power saving mode but also when the normal mode is restored. That is, when the connection or session in the previous normal mode is not maintained, the connection is disconnected and a response cannot be returned, and thus the same problem as described above occurs.

  The present invention has been made in view of the above problems, and an object thereof is to enable a proxy response to be realized in the power saving mode even in a connection-type communication protocol or a protocol for performing session establishment processing. It is another object of the present invention to provide a power saving mode control method that allows the main CPU to continue communication via a connection or session when returning from the normal mode.

In order to solve the above problems, an information processing apparatus according to one embodiment of the present invention includes the following arrangement. That is,
A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication . a mode and an information processing apparatus wherein the sub-system operates by switching a second mode for controlling communication with uncontrolled of the main system,
When you are pre Symbol waits for reception of packets have you in connection communication application is established, the shifting unit to shift to the second mode,
In the sub-system, maintaining a connection identifier and a connection status of the connection, and maintaining the connection ,
And instruction means for instructing the return to the first mode to the main system from the previous SL second mode,
Before SL instructions in accordance with the previous SL anda return means for returning the to the first mode of the main system as the communication application communication in the connection being maintained by the subsystem continues,
The transition means stops the communication application upon transition to the second mode,
The return means includes
In response to the instruction, start the communication application,
Depending on the establishment request of connection launched the communication application is performed, it notifies the connection identifier of the connection is maintained by the sub-system to the communication application.

  According to the present invention, a proxy response can be realized in the power saving mode even in a connection-type communication protocol or a protocol for performing session establishment processing. Even when a request is generated by a connection type protocol or a protocol for establishing a session, a response can be returned in the power saving mode. Therefore, the network device can maintain the power saving mode, so that power consumption can be reduced.

  Also, since the connection and session are maintained, the time from when the network device returns to the normal mode until communication with another terminal becomes possible can be shortened.

The block diagram of the system in embodiment. The software block diagram in 1st embodiment. The flowchart at the time of the normal mode in 1st embodiment. The sequence diagram at the time of power saving mode transition / normal mode return of the first embodiment. The flowchart of the proxy response process at the time of the power saving mode by 1st embodiment. The sequence diagram at the time of power saving mode transition / normal mode return of the second embodiment. The sequence diagram at the time of power saving mode transition / normal mode recovery of the third embodiment. The sequence diagram at the time of power saving mode transition / normal mode return of the fourth embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
<First embodiment>
FIG. 1 shows a system configuration diagram of the information processing apparatus according to the first embodiment of the present invention. In the information processing apparatus 101, the main system 102 has a main CPU (not shown) and performs application processing. The application process corresponds to, for example, a print control process when the information processing apparatus 101 is a printing apparatus. The sub system 103 has a sub CPU (not shown), and communicates with the PC 108 on the network 107 by performing TCP / IP processing and controlling the communication unit 106. The main system 102 and the subsystem 103 perform inter-CPU communication via the inter-CPU communication register 105. When one CPU writes data to the inter-CPU communication register 105, an interrupt is generated in the other CPU, and the other CPU can read the data. Programs executed by the main system 102 and the subsystem 103 are arranged in the shared memory 104. As will be described later, the subsystem 103 performs connection-type communication with an external device (PC 108) under the control of the main system. The storage unit 110 and the ROM 120 can be omitted because they are not used in the first embodiment.

  The information processing apparatus 101 is connected to the network 107 via the communication unit 106. The PC 108 connected to the network 107 transmits a status confirmation packet and an application processing request to the information processing apparatus 101. The status confirmation packet is a packet for checking whether the information processing apparatus 101 can respond. When the information processing apparatus 101 receives the status confirmation packet from the PC 108, it transmits a status confirmation response packet to the PC 108. The application processing request packet is a packet for requesting application processing to the information processing apparatus 101. When the information processing apparatus 101 is a printing apparatus, a print job or the like corresponds to an application processing request packet. When the information processing apparatus 101 receives the application processing request packet, the information processing apparatus 101 performs application processing.

  FIG. 2 illustrates a software configuration example of the information processing apparatus 101. A program executed by the main system 102 includes a communication application 201 and an embedded OS 202. A program executed by the subsystem 103 is the network control unit 203. Each program is arranged in the shared memory 104.

  A general BSD socket API is implemented in the embedded OS 202, and the entity of socket processing is implemented in the network control unit 203. The communication application 201 makes a socket request, connection establishment request, received packet request, etc. to the network control unit 203 via the BSD socket API implemented in the embedded OS 202. Communication between the embedded OS 202 and the network control unit 203 is realized using the inter-CPU communication register 105. The communication application 201 uses the BSD socket API to receive a request from the PC 108 and perform application processing. The communication application 201 is activated and stopped by the embedded OS 202.

  The network control unit 203 performs TCP / IP processing and control processing of the communication unit 106 in the normal mode. The network control unit 203 receives a request from the main system 102 via the BSD socket API, processes each request, and returns a response. The request from the BSD socket API includes a socket request, a connection connection establishment request, a received packet request, and a packet transmission. In addition to the above processing, the network control unit 203 performs proxy response processing of the communication application 201 in the power saving mode. In the proxy response process, a process of returning a response packet for a process that does not require the process of the main system 102 is performed on the packet received from the PC 108 in the power saving mode. Here, a status confirmation response packet is returned to the PC 108 for the status confirmation packet. When an application processing request packet is received, the power saving mode returns to the normal mode, and the communication application 201 performs processing in the normal mode.

  The operation in the normal mode will be described with reference to FIG. The information processing apparatus 101 performs connection-type communication with the PC 108 on the network 107. Communication with the PC 108 establishes a TCP connection, and all subsequent communication is performed via the connection. FIG. 3 shows details of processing of the communication application 201 and the network control unit 203 until the connection is established in the normal mode and actual packet transmission / reception becomes possible.

  First, a connection establishment process is performed. In establishing a connection, first, the communication application 201 makes a socket request to the network control unit 203 (S301). On the other hand, the network control unit 203 passes the socket descriptor A to the communication application (S302). The communication application 201 uses the received socket descriptor A for connection establishment. The communication application 201 requests the network control unit 203 to establish a connection using the socket descriptor A (S303). At this time, the communication application 201 designates a port number for establishing a connection. When establishing a connection with the PC 108, the network control unit 203 notifies the communication application 201 of a socket descriptor B for performing transmission / reception through the established connection (S304). With the above processing, establishment of a connection with the PC 108 is completed.

  Next, a method for transmitting and receiving packets via an established connection will be described. The communication application 201 issues a received packet request using the socket descriptor B notified in S304 (S305). When receiving the request for the received packet, the network control unit 203 stores the socket descriptor B as a packet waiting socket descriptor (S306). Thereafter, the network control unit 203 waits for a packet from the PC 108 (S307). The network control unit 203 receives the packet from the PC 108 (S308), cancels the socket descriptor B from the socket descriptor waiting for the packet (S309), and notifies the communication application of the received packet (S310).

  In this way, by repeatedly issuing a request for a received packet and notifying the received packet using the socket descriptor, it is possible to receive a status confirmation packet and an application processing request packet from the PC 108. Further, the communication application 201 can transmit a packet to the PC 108 by requesting the network control unit 203 to transmit a packet using the socket descriptor B.

  Next, a method for shifting from the normal mode to the power saving mode and a method for returning from the power saving mode to the normal mode in the information processing apparatus 101 will be described with reference to FIG. First, the power saving mode transition method will be described. It is assumed that the information processing apparatus 101 has established a connection with the PC 108 by the processing shown in FIG. 3 before shifting to the power saving mode. In order to receive the packet from the PC 108, the communication application 201 makes a request for the received packet with the socket descriptor B to the network control unit 203 (S401). Even before shifting to the power saving mode, the communication application 201 requests the received packet with the socket descriptor B (S401). Upon receiving this request, the network control unit 203 saves the socket descriptor B as a socket descriptor waiting for packet reception (S402), and waits for reception of a packet from the PC 108 (S403). Here, the network control unit 203 holds a socket descriptor as a connection identifier and a connection status in association with each other. The connection status is information necessary for connection-type communication. For example, in the case of TCP / IP, the connection status is information necessary for TCP / IP stack processing. Specifically, the IP address / port number of the own / destination, TCP sequence number, ACK number, session flag, etc. included. The network control unit 203 performs TCP / IP stack processing on the received data and transmission data using the connection status, and makes a proxy response.

  In order for the information processing apparatus 101 to shift to the power saving mode, the embedded OS 202 first starts by notifying the network control unit 203 of shifting to the power saving mode (S404). Then, the embedded OS 202 stops the communication application 201 (S405). Further, in the power saving mode, it is desirable to make the power consumption as small as possible by, for example, clocking down the main system 102. In the above description, the embedded OS 202 has stopped the communication application 201 (S405) when the communication application 201 has transmitted a request for a received packet to the network control unit 203. However, if the embedded OS 202 attempts to stop the communication application 201 when the communication application 201 has not yet transmitted a received packet request to the network control unit 203, the communication application 201 transmits a received packet request. Stop operation from.

  Upon receiving the notification of the power saving mode transition (S404), the network control unit 203 transitions to the power saving mode while maintaining the connection with the PC 108 without stopping the processing. For this reason, the own IP address and port number necessary for TCP / IP processing, and the IP address and port number of the connection destination are retained. Further, the sequence number, ACK number, session flag, etc. of the TCP packet are also held in the network control unit 203.

  Next, the operation in the power saving mode will be described. Even if the network control unit 203 receives the notification of transition to the power saving mode in S404, the network control unit 203 performs proxy response processing while maintaining the connection with the PC 108 without stopping (S406). FIG. 5 shows details of proxy response processing by the network control unit 203.

  As shown in S501, the network control unit 203 continues to wait until a packet is received. When receiving a packet from the PC 108 via the maintained connection, the network control unit 203 determines whether the packet can be responded by itself (S502). As a result of the determination, if it is a state confirmation packet, a state confirmation response packet is transmitted to the PC 108 via the connection (S503). When the response packet is transmitted, it waits for packet reception again.

  On the other hand, when it is determined in S502 that the packet cannot be responded to the packet received from the PC 108, the network control unit 203 determines whether the received packet is a packet that should be returned to the normal mode (S504). If the packet does not need to return to the normal mode and can be discarded, the process returns to S501, and the network control unit 203 again waits for reception of a packet from the PC. On the other hand, if it is determined in S504 that the packet should be returned to the normal mode, that is, if the received packet is an application processing request request packet, the proxy response process is terminated and the normal mode is returned from the power saving mode. To do.

  Next, a sequence when returning from the power saving mode to the normal mode will be described. In FIG. 4, when the proxy response process of S406 is completed, the normal mode return process is started. In the normal mode return processing, first, the network control unit 203 stores a received packet that is a trigger for returning to the normal mode (S407). Then, the network control unit 203 notifies the embedded OS 202 that controls the main system 102 of the return to the normal mode (S408).

  When the embedded OS 202 receives the normal mode return from the network control unit 203, the embedded OS 202 starts the normal mode return processing. Here, when the clock of the main system 102 is down in the power saving mode, processing such as restoring the clock is performed. Since the embedded OS 202 has stopped the communication application 201 when shifting to the power saving mode, the embedded OS 202 newly starts the communication application 201 (S409). Since the communication application 201 started in S409 does not have the information in the previous normal mode, the connection is again established as shown in S301 to S304 in FIG. 3 and packet transmission / reception is started. However, when returning to the normal mode, steps S410 to S416 in FIG. 4 are executed.

  First, the communication application 201 issues a socket request to the network control unit 203 (S410). Then, the network control unit 203 newly notifies the socket descriptor C (S411). Then, the communication application 201 uses the socket descriptor C to make a connection establishment request (S412). At this time, the communication application 201 designates a port number for establishing a connection.

  When the network control unit 203 receives the connection establishment request, the network control unit 203 searches the reception waiting socket descriptor stored in S402 for the same port number specified in S412 (S413). If the port number received in S412 is the same port number as the socket descriptor B stored in S402, the socket descriptor B is notified to the communication application 201 (S414). As a result, the communication application 201 recovers the original connection information and can communicate with the PC 108 again through the connection. That is, in returning to the normal mode, the communication application 201 can continue communication using the connection maintained in the subsystem 103.

  When the communication application 201 recovers the connection, the communication application 201 requests a received packet (S415). Upon receiving the received packet request, the network control unit 203 returns the received packet stored in S407 to the communication application 201 (S416). Thereby, the packet received in the power saving mode and stored in S407 can be passed to the communication application 201. The communication application 201 receives the received packet, that is, an application processing request request packet, and performs application processing.

<Second embodiment>
The system configuration in the second embodiment is as described in FIG. However, in the second embodiment, the storage unit 110 as network storage is used. The storage unit 110 is an external storage device. The external storage device may be a memory card such as a compact flash or an SD card, or a fixed disk such as a hard disk drive. A plurality of files can be stored in the storage unit 110 of the information processing apparatus 101. The PC 108 accesses a file on the storage unit 110 via the network 107. Here, the SMB protocol is used as a protocol for file sharing via the network. In this embodiment, the SMB protocol uses TCP as a transport layer.

  The PC 108 transmits a file read request and a write request on the storage unit 110 to the information processing apparatus 101 using the SMB protocol. When receiving the request, the information processing apparatus 101 accesses the storage unit 110 in response to the request. The actual SMB protocol request processing is performed by the communication application 201 executed by the main system 102.

  Further, the PC 108 periodically transmits an SMB echo request to the information processing apparatus 101. The SMB echo request is a request for confirming the state of the counterpart terminal in the SMB protocol. When receiving the SMB echo request, the information processing apparatus 101 returns an SMB echo response to the PC 108. The PC 108 determines that the storage unit 110 of the information processing apparatus 101 is accessible by receiving the SMB echo response.

  The software configuration in the information processing apparatus 101 of this embodiment is shown in FIG. 2 as in the first embodiment. That is, as in the first embodiment, the network control unit is controlled via the BSD socket API implemented in the embedded OS 202 to perform network communication. However, in the second embodiment, the communication application 201 performs SMB protocol processing. The communication application 201 accesses the storage unit 110 in response to a request from the PC 108 and performs processing such as file writing and file reading.

  The network control unit 203 performs proxy response processing of the communication application 201 in the power saving mode. In this proxy response process, when an SMB echo request is received from the PC 108, a process of returning an SMB echo response is performed. In the case of a request to access a file on the storage unit 110, the information processing apparatus 101 returns from the power saving mode to the normal mode. Then, after returning to the normal mode, the communication application 201 performs processing corresponding to the request.

  Hereinafter, the operation in the normal mode will be described. First, processing until the PC 108 can access the storage unit 110 via the SMB protocol will be described with reference to FIG. First, the PC 108 establishes a TCP connection with the information processing apparatus 101. In the information processing apparatus 101, the communication application 201 and the network control unit 203 perform the processing from S301 to S304 in FIG. Thereby, the network control unit holds the connection with the PC 108, and the communication application 201 can communicate with the PC 108 via the connection using the acquired socket descriptor (socket descriptor B in the example of FIG. 3). it can.

  Next, an SMB protocol session is established between the information processing apparatus 101 and the PC 108 via the established connection. In establishing an SMB session, the SMB protocol function level is matched between terminals, and user authentication processing is performed. In the function level matching, the information processing apparatus 101 acquires the function level (for example, protocol version) of the SMB protocol that can be implemented by the PC 108 from the PC 108. The communication application 201 holds the acquired function level of the SMB protocol. The communication application 201 makes a request / response to the PC 108 on the SMB protocol with the PC 108 according to the acquired function level of the SMB protocol. In the user authentication process, the information processing apparatus 101 acquires a user name and password from the PC 108. The communication application 201 determines whether the user is authorized to access from the acquired user name and password (or is a user authorized to access each file). Notify that user authentication was successful.

  Through the above SMB session establishment process, the communication application 201 acquires the SMB protocol function level and user information, which are necessary information, for exchanging with the PC 108 using the SMB protocol. Information including the above-described protocol function level and user authentication information is referred to as an application status. When the TCP connection establishment and the SMB session establishment are completed, the PC 108 can access the storage unit 110 via the SMB protocol.

  In the normal mode, when the information processing apparatus 101 receives a packet, the communication application 201 and the network control unit 203 perform processing in the same procedure as in FIG. 3 (S305 to S310) of the first embodiment. Further, the information processing apparatus 101 receives a request for accessing a file on the storage unit 110 from the PC 108 and a SMB echo request periodically in the normal mode. Upon receiving these requests, the network control unit 203 performs TCP / IP processing, the communication application 201 performs SMB protocol processing, and returns a response to the PC 108.

  A transition method from the normal mode to the power saving mode and a return method from the power saving mode to the normal mode in the information processing apparatus 101 will be described with reference to FIG.

  First, the power saving mode transition method will be described. In order to receive the packet from the PC 108, the communication application 201 requests the received packet from the network control unit 203 (S601). When the communication application 201 requests a received packet, the communication application 201 blocks (waits for processing other than waiting for the received packet) while waiting for the received packet (S607). When receiving the request for the received packet, the network control unit 203 waits for the packet (S602).

  In order for the information processing apparatus 101 to shift to the power saving mode, first, the embedded OS 202 notifies the network control unit 203 of shifting to the power saving mode (S603). After the notification of transition to the power saving mode, it is desirable that the embedded OS 202 be configured to reduce power consumption in the power saving mode as much as possible by, for example, clocking down the main system 102.

  Even after shifting to the power saving mode, the communication application 201 blocks while waiting for the received packet for the received packet request made in S601, and waits until the received packet is notified from the network control unit 203 (S607). Although the communication application 201 is in the blocking state but shifts to the power saving mode while being activated, the socket descriptor, the SMB protocol function level of the PC 108 and the user information are retained. Therefore, if the packet is notified and blocking is released, the SMB protocol processing can be performed as it is.

  As described above, the network control unit 203 shifts to the power saving mode while maintaining the connection with the PC 108 without stopping when receiving the notification of shifting to the power saving mode in S603. For this reason, the IP address and port number of the host / connection destination necessary for TCP / IP processing are held. Further, the sequence number, ACK number, session flag, etc. of the TCP packet necessary for the analysis of the TCP packet are also held in the network control unit 203.

  Next, the operation in the power saving mode will be described. The network control unit 203 performs the proxy response process of S604 while maintaining the connection as in the first embodiment. The proxy response process is shown in FIG. 5 as in the first embodiment. In the second embodiment, the network control unit 203 determines in S502 that the received packet is a response packet if it is an SMB echo request, and transmits an SMB echo response to the PC 108 in S503. As a result, even in the power saving mode, a response can be returned to the status confirmation from the PC 108 that is periodically performed. On the other hand, if the received packet is a packet other than the SMB echo request, the network control unit 203 determines that the packet cannot be responded, and executes S504. If the packet is a request for access to a file on the storage unit 110 in S504, the network control unit 203 determines that the normal mode should be restored, and ends the proxy response process.

Next, a sequence for returning from the power saving mode to the normal mode will be described with reference to FIG.
When the proxy response process of S604 is completed, the network control unit 203 notifies the embedded OS 202 of the return to the normal mode (S605). When the embedded OS 202 receives the notification of the return to the normal mode, if the clock of the main system 102 has been reduced in S603, the embedded OS 202 performs processing such as returning the clock. Next, the network control unit 203 notifies the communication application 201 that has blocked the packet that has been determined to be a trigger for returning to the normal mode in S504, waiting for the received packet (S606).

  Upon receiving this received packet, the communication application 201 cancels blocking. The communication application 201 remains blocked during the transition from the normal mode to the power saving mode and from the power saving mode to the return to the normal mode. Therefore, since the information necessary for performing the SMB protocol processing such as the socket descriptor, the SMB protocol function level of the PC 108 and the user information is retained, the communication application 201 processes the received packet using the information. . Thereby, the communication application 201 can process the request received in the power saving mode in the normal mode. That is, the communication application 201 performs SMB protocol processing such as accessing the storage unit 110 or returning a response to the PC 108 in accordance with the request content from the PC 108. In this way, in the return to the normal mode, the communication application 201 can continue communication using the connection maintained in the subsystem 103.

<Third embodiment>
The system configuration in the third embodiment is as described in FIG. However, in the third embodiment, the ROM 120 is further used. In the third embodiment, the PC 108 accesses the file in the storage unit 110 of the information processing apparatus 101 via the network 107 as in the second embodiment. In addition, the SMB protocol is used as a communication protocol. The software configuration of the third embodiment is shown in FIG. 2, and the communication application 201, the embedded OS 202, and the network control unit 203 perform the same processing as that of the second embodiment. The difference from the second embodiment is a method for shifting from the normal mode to the power saving mode and a method for returning from the power saving mode to the normal mode (FIG. 7). The operations in the normal mode and the power saving mode are the same as in the second embodiment.

First, a method for shifting from the normal mode to the power saving mode will be described.
Before shifting to the power saving mode, the communication application 201 makes a request for a received packet to the network control unit 203 as in the second embodiment (S701). In response to the received packet request, the network control unit 203 waits for a packet from the PC 108 (S702).

  When shifting to the power saving mode, the embedded OS 202 notifies the network control unit 203 of shifting to the power saving mode (S703). Further, the embedded OS 202 sends a stop request to instruct the communication application 201 to stop (S704). Receiving the stop request, the communication application 201 stores the socket descriptor, the corresponding SMB protocol function level, and user information (user authentication information) in the ROM 120 as the application status before stopping itself (S705). If the request for the received packet is not sent to the network control unit 203, the request for the received packet is transmitted to the network control unit 203. When these processes are completed, the communication application 201 instructed to stop stops the processes. On the other hand, when the network control unit 203 receives the notification of the power saving mode transition in S703, it performs proxy response processing (S706). The proxy response process is the same process as in the second embodiment. With the above processing, the normal mode is shifted to the power saving mode.

  Next, a method for returning from the power saving mode to the normal mode will be described. When the proxy response process (S706) is completed in the same manner as in the second embodiment, the network control unit 203 stores the received packet that triggered the return to the normal mode (S707). Then, the network control unit 203 notifies the embedded OS 202 that the normal mode is restored (S708).

  When the embedded OS 202 receives the normal mode return from the network control unit 203, the embedded OS 202 starts the normal mode return processing. Since the embedded OS 202 has stopped the communication application 201 in the power saving mode, the embedded OS 202 starts up the communication application 201 again (S709). When the communication application 201 is activated, it acquires a socket descriptor, a corresponding SMB protocol function level, and user information from the ROM 120 as information when operating in the normal mode last time (S710). The communication application 201 can resume communication with the PC 108 using these pieces of information. In other words, in the return to the normal mode, the communication application 201 can continue communication using the connection maintained in the subsystem 103.

  Subsequently, the communication application 201 requests the received packet from the network control unit 203 (S711). When receiving the request, the network control unit 203 notifies the communication application 201 of the received packet stored in S707 without waiting for the received packet (S712). Through the above processing, the normal mode can be restored and the communication processing by the communication application 201 can be resumed.

<Fourth embodiment>
The fourth embodiment is different from the third embodiment in a method for shifting from the normal mode to the power saving mode and a method for returning from the power saving mode to the normal mode. A power saving mode transition method and a normal mode return method according to the fourth embodiment will be described with reference to FIG.

  The processing from S801 to S803 is the same as S701 to S703 (FIG. 7) of the third embodiment. The embedded OS 202 transmits a stop request to the communication application 201 after notifying the network control unit 203 of transition to the power saving mode (S804). Upon receiving the stop request, the communication application 201 transmits a socket descriptor, a corresponding SMB protocol function level, and user information as an application status to the network control unit 203 (S805). After transmitting the application status, the communication application 201 stops. Upon receiving the application status, the network control unit 203 performs proxy response processing while retaining the information until the normal mode is restored (S806). With the above processing, the normal mode is shifted to the power saving mode.

  Next, processing for returning from the power saving mode to the normal mode will be described. The processing from S806 to S809 is the same as S706 to S709 in the third embodiment.

  The communication application 201 started in S809 first requests the network control unit 203 for operation information of the previous normal mode, that is, an application status (S810). In this example, the application status includes a socket descriptor, a corresponding SMB protocol function level, and user information. When receiving the request, the network control unit 203 transmits the requested information (application status) to the communication application 201 (S811). Thereby, the communication application 201 can acquire the operation information of the previous normal mode, that is, the application status from the network control unit 203, and can resume the communication processing in a state where the SMB session with the PC 108 is established. In other words, in the return to the normal mode, the communication application 201 can continue communication using the connection maintained in the subsystem 103. In addition, the communication application 201 acquires the packet that triggered the return to the normal mode by the same method as in the third embodiment (S812, S813). As a result, the processing in the normal mode can be resumed.

<About other embodiments>
Each embodiment mentioned above is a suitable embodiment of the present invention, and the present invention is not limited to this but can be carried out in various forms.

  For example, in each embodiment, the embedded OS 202 remains operating in the power saving mode, but the present invention is not limited to this state, and the embedded OS 202 may be stopped. In that case, a minimum program for detecting the normal mode return notification from the network control unit 203 is operated on the main system 102, and the embedded OS 202 is restarted when the normal mode return notification is received. .

  In the second, third, and fourth embodiments, the request for proxy response in the power saving mode is only the SMB echo request, but other requests may be used. For example, a proxy response may be made to a shared resource list request or the like. For example, in the fourth embodiment, the shared resource list information is notified from the communication application 201 to the network control unit 203 as one of the application statuses in S804 of FIG. And at the time of proxy response, it responds to a request using this shared resource list information. By adopting such a method, the present invention can make a proxy response to other various requests.

  In each embodiment, the packet that triggers the return to the normal mode is a packet received via the connection, but may be another packet. That is, a packet to be transmitted without establishing a connection, for example, a Wake On LAN Magic Packet may be used as a trigger packet. Alternatively, a TCP connection establishment request packet or the like may be used as a trigger for activation.

Claims (11)

A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication . a mode and an information processing apparatus wherein the sub-system operates by switching a second mode for controlling communication with uncontrolled of the main system,
When you are pre Symbol waits for reception of packets have you in connection communication application is established, the shifting unit to shift to the second mode,
In the sub-system, maintaining a connection identifier and a connection status of the connection, and maintaining the connection ,
And instruction means for instructing the return to the first mode to the main system from the previous SL second mode,
Before SL instructions in accordance with the previous SL anda return means for returning the to the first mode of the main system as the communication application communication in the connection being maintained by the subsystem continues,
The transition means stops the communication application upon transition to the second mode,
The return means includes
In response to the instruction, start the communication application,
Depending on the establishment request of connection it launched the communication application is performed, the information processing apparatus characterized that you notice the connection identifier of the connection is maintained by the sub-system to the communication application.   The maintaining means executes the proxy response processing of the communication application while maintaining the connection,
  The instruction means instructs the main system to return from the second mode to the first mode when a packet that requires processing by the communication application is received in the proxy response processing. The information processing apparatus according to claim 1. It said return means, the information processing apparatus according to claim 1 or 2, wherein the notifying the connection identifier corresponding to the connection status including the port number included in the establishment request to the communication application. A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And an information processing apparatus that operates by switching between the second mode in which the subsystem performs communication control under non-control of the main system,
A transition means for transitioning to the second mode when waiting for reception of a packet in the connection established by the communication application;
In the sub-system, maintaining a connection identifier and a connection status of the connection, and maintaining the connection,
Instruction means for instructing the main system to return from the second mode to the first mode;
In response to the instruction, a return means for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem, and
While the communication application is waiting to receive a packet, the communication application enters a blocking state in which processing other than the reception waiting is stopped, and the blocking state is maintained in the second mode,
It said return means, the information you and cancels the state of the blocking by the communication application by processing packets that need to be notified to the communication application processing unit. A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And an information processing apparatus that operates by switching between the second mode in which the subsystem performs communication control under non-control of the main system,
A transition means for transitioning to the second mode when waiting for reception of a packet in the connection established by the communication application;
In the sub-system, maintaining a connection identifier and a connection status of the connection, and maintaining the connection,
Instruction means for instructing the main system to return from the second mode to the first mode;
In response to the instruction, a return means for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem, and
The communication application further performs communication through the connection using an application status including information indicating a user authentication information or a protocol function level in the connection,
Upon shifting to the second mode, the communication application holds the application status and the connection identifier in a memory and stops,
It said return means, information processing apparatus you characterized in that to continue the connection using the said connection identifier held in said memory to said communication application application status. A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And an information processing apparatus that operates by switching between the second mode in which the subsystem performs communication control under non-control of the main system,
A transition means for transitioning to the second mode when waiting for reception of a packet in the connection established by the communication application;
In the sub-system, maintaining a connection identifier and a connection status of the connection, and maintaining the connection,
Instruction means for instructing the main system to return from the second mode to the first mode;
In response to the instruction, a return means for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem, and
The communication application further performs communication through the connection using an application status including information indicating a user authentication information or a protocol function level in the connection,
Upon transition to the second mode, the communication application stops the application status and the connection identifier held in the subsystem,
It said return means, the said and the connection identifier stored in the subsystem the application status is obtained from the subsystem to the communications application, information processing apparatus you characterized in that to continue the connection. After returning to the first mode by the return means, the communication application receives a packet that is received by the proxy response process and needs to be processed by the communication application in response to a request for reception of the packet by the communication application. The information processing apparatus according to claim 2 , further comprising notification means for performing the operation. A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication . And a method of controlling an information processing apparatus that operates by switching between the mode and the second mode in which the subsystem controls communication under non-control of the main system ,
Said main system, when where it is waiting for the reception of a packet have you to the connection by the communication application is established, the transition process to transition to the second mode,
In the sub-system, a step maintains that holds the connection identifier and connection status before Symbol connection, maintaining the connection,
Indicating means, and before Symbol second mode indication step of indicating a return to the first mode to the main system,
Return means comprises a return process in accordance with the prior SL instructions, thereby pre-Symbol returning the main system as the communication application communication in the connection is maintained to continue in the sub-system to the first mode, I have a,
In the transition step, the communication application is stopped upon transition to the second mode,
In the return step,
In response to the instruction, start the communication application,
A method for controlling an information processing apparatus, comprising: notifying a communication application of a connection identifier of the connection maintained in the subsystem in response to a connection establishment request made by the started communication application .   A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And a method of controlling an information processing apparatus that operates by switching between the mode and the second mode in which the subsystem controls communication under non-control of the main system,
  When the main system waits for reception of a packet in the connection established by the communication application, and transitions to the second mode;
  In the subsystem, maintaining a connection identifier and a connection status of the connection, maintaining the connection,
  An instruction step for instructing the main system to return from the second mode to the first mode;
  A return step for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem in response to the instruction; ,
  While the communication application is waiting to receive a packet, the communication application enters a blocking state in which processing other than the reception waiting is stopped, and the blocking state is maintained in the second mode,
  In the return step, the blocking state is canceled by notifying the communication application of a packet that needs to be processed by the communication application.   A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And a method of controlling an information processing apparatus that operates by switching between the mode and the second mode in which the subsystem controls communication under non-control of the main system,
  When the main system waits for reception of a packet in the connection established by the communication application, and transitions to the second mode;
  In the subsystem, maintaining a connection identifier and a connection status of the connection, maintaining the connection,
  An instruction step for instructing the main system to return from the second mode to the first mode;
  A return step for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem in response to the instruction; ,
  The communication application further performs communication through the connection using an application status including information indicating a user authentication information or a protocol function level in the connection,
  Upon shifting to the second mode, the communication application holds the application status and the connection identifier in a memory and stops,
  In the return step, the connection is continued using the connection identifier held in the memory and the application status in the communication application, and the control method of the information processing apparatus,   A main system that executes a communication application; and a subsystem that performs connection-type communication with an external device under the control of the main system. The main system controls the subsystem to control communication. And a method of controlling an information processing apparatus that operates by switching between the mode and the second mode in which the subsystem controls communication under non-control of the main system,
  When the main system waits for reception of a packet in the connection established by the communication application, and transitions to the second mode;
  In the subsystem, maintaining a connection identifier and a connection status of the connection, maintaining the connection,
  An instruction step for instructing the main system to return from the second mode to the first mode;
  A return step for returning the main system to the first mode so that the communication application continues communication in the connection maintained in the subsystem in response to the instruction; ,
  The communication application further performs communication through the connection using an application status including information indicating a user authentication information or a protocol function level in the connection,
  Upon transition to the second mode, the communication application stops the application status and the connection identifier held in the subsystem,
  In the returning step, the communication application is caused to acquire the connection identifier and the application status held in the subsystem from the subsystem, and the connection is continued.

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