modem: modem_cmux: Increase modem cmux buf size #63812
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This commit increases the buffer used for commands in the control channel within an instance of the modem_cmux module. The buffer was not large enough to store an MSC command if the optional break signals where included. This commit fixes the issue and updates the test suite to use the max size MSC message. Signed-off-by: Bjarki Arge Andreasen <baa@trackunit.com>
This commit adjust the chat scripts for the simcom sim7080 and gsm_ppp compatibles to fix an issue found when trying to use a sim7080 modem. The CMUX command includes optional parameters which are not identical for all modems, so the AT+CMUX command has been adjusted to only contain the mandatory parameters. Signed-off-by: Bjarki Arge Andreasen <baa@trackunit.com>
| @@ -1365,8 +1364,7 @@ MODEM_CHAT_SCRIPT_CMDS_DEFINE(simcom_sim7080_init_chat_script_cmds, | |||
| MODEM_CHAT_SCRIPT_CMD_RESP("AT+CGSN", imei_match), | |||
| MODEM_CHAT_SCRIPT_CMD_RESP("", ok_match), | |||
| MODEM_CHAT_SCRIPT_CMD_RESP("AT+CGMM", cgmm_match), | |||
| MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT+CMUX=0,0,5,127,10,3,30,10,2", | |||
| 0)); | |||
| MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT+CMUX=0,0,5,127", 300)); | |||
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non blocker: FWIW SIM7080 does support N1, T1, N2 and T2 options, and simply not T3 and K like BG95 has, and they are defaulting respectively to 118, 0, 0, 600. Would it make sense to stick to the below, or does it makes no useful difference?
| MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT+CMUX=0,0,5,127", 300)); | |
| MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT+CMUX=0,0,5,127,10,3,30", 300)); |
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The defaults are 0,0,600 as the maximum frame size is set to 127. The maximum frame size is important as the modem_cmux instance internal buffer is scaled to this value. The T1 and N2 are not used or not configurable for the SIM7080, so it really won't matter what we set them to. I would prefer them and T2 to be default.
| @@ -23,7 +23,7 @@ LOG_MODULE_REGISTER(modem_cmux, CONFIG_MODEM_MODULES_LOG_LEVEL); | |||
| #define MODEM_CMUX_DATA_FRAME_SIZE_MIN (MODEM_CMUX_FRAME_SIZE_MAX + \ | |||
| MODEM_CMUX_DATA_SIZE_MIN) | |||
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| #define MODEM_CMUX_CMD_DATA_SIZE_MAX (0x04) | |||
| #define MODEM_CMUX_CMD_DATA_SIZE_MAX (0x08) | |||
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Confirmed as working. I had initially tested with 0x10 but 0x08 seems to be enough to get rid of the buffer overrun I was seeing otherwise.
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Nice :) I replicated the exact data that was sent from your modem in the CMUX unit test which is why I decided to go with a smaller buffer with confidence :)
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Thanks @kartben for retesting it! |
This PR fixes two issues preventing the
modem_cellular.cdriver from connecting and configuring CMUX for the SIMCOM SIM7080 modem.Increases the buffer used for commands in the control channel within an instance of the
modem_cmux module. The buffer was not large enough to store an MSC command if the optional break signals where included. This commit fixes the issue and updates the test suite to use the max size MSC message.
Adjust
AT+CMUXchat script requests to only contain required parameters.Fixes #63813