[PATCH] serial: allow specifying baudrate to use via udev tags

Wed Mar 22 17:02:42 UTC 2017

Hello Aleksander,

When you are saying not to mix e-mail threads you mean not to reply all? I am only replying to e-mails which are related to my problem. I have done mmcli -S and that command response with "successfully requested to scan devices". Here is the output from ModemManager debug session:

ModemManager[1532]: <debug> [1490186663.752548] [mm-plugin.c:767] mm_plugin_supports_port(): (Generic) [ttymxc2] probe required: 'at, qcdm'
ModemManager[1532]: <debug> [1490186663.752733] [mm-port-probe.c:1353] mm_port_probe_run(): (tty/ttymxc2) launching port probing: 'qcdm'
ModemManager[1532]: <debug> [1490186663.752965] [mm-port-probe.c:658] serial_probe_qcdm(): (tty/ttymxc2) probing QCDM...
ModemManager[1532]: <debug> [1490186663.753384] [mm-port-serial.c:1099] mm_port_serial_open(): (ttymxc2) opening serial port...
ModemManager[1532]: <debug> [1490186663.755754] [mm-port-serial.c:1237] mm_port_serial_open(): (ttymxc2) device open count is 1 (open)
ModemManager[1532]: <debug> [1490186663.756270] [mm-port-serial-qcdm.c:201] debug_log(): (ttymxc2): --> 7e 00 78 f0 7e
ModemManager[1532]: <debug> [1490186666.742982] [mm-port-serial-qcdm.c:201] debug_log(): (ttymxc2): --> 7e 00 78 f0 7e
ModemManager[1532]: <debug> [1490186669.743253] [mm-port-probe.c:258] mm_port_probe_set_result_qcdm(): (tty/ttymxc2) port is not QCDM-capable
ModemManager[1532]: <debug> [1490186669.746282] [mm-port-serial.c:1296] mm_port_serial_close(): (ttymxc2) device open count is 0 (close)
ModemManager[1532]: <debug> [1490186669.748909] [mm-port-serial.c:1312] mm_port_serial_close(): (ttymxc2) closing serial port...
ModemManager[1532]: <debug> [1490186669.759468] [mm-port-serial.c:1361] mm_port_serial_close(): (ttymxc2) serial port closed
ModemManager[1532]: <debug> [1490186669.759689] [mm-port-serial.c:1415] port_serial_close_force(): (ttymxc2) forced to close port
ModemManager[1532]: <debug> [1490186669.760001] [mm-plugin-manager.c:462] plugin_supports_port_ready(): (Plugin Manager) (Generic) [ttymxc2] found best plugin for port
ModemManager[1532]: <debug> [1490186669.760300] [mm-plugin-manager.c:316] port_probe_context_finished(): (Plugin Manager) 'ttymxc2' port probe finished, last one in device
ModemManager[1532]: <debug> [1490186669.760459] [mm-plugin-manager.c:138] find_device_support_context_complete_and_free(): (Plugin Manager) [/sys/devices/soc0/soc/2100000.aips-bus/21ec000.serial] device support check finished in '15.800204' seconds
ModemManager[1532]: <info>  [1490186669.760657] [mm-device.c:509] mm_device_create_modem(): Creating modem with plugin 'Generic' and '1' ports
ModemManager[1532]: <warn>  [1490186669.773671] [mm-plugin.c:905] mm_plugin_create_modem(): Could not grab port (tty/ttymxc2): 'Cannot add port 'tty/ttymxc2', unhandled serial type'
ModemManager[1532]: <debug> [1490186669.774134] [mm-base-modem.c:1485] finalize(): Modem (Generic) '/sys/devices/soc0/soc/2100000.aips-bus/21ec000.serial' completely disposed
ModemManager[1532]: <warn>  [1490186669.774314] [mm-base-manager.c:158] find_device_support_ready(): Couldn't create modem for device at '/sys/devices/soc0/soc/2100000.aips-bus/21ec000.serial': Failed to find primary AT port

It looks like the ttymxc2 modem port is not QCDM-capable. Is there anything I can do to make it QCDM-capable? The ModemManager software version running on my development board is 1.4.0. Does this make difference?

Best Regards,
Jan Graczyk

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-----Original Message-----
From: Aleksander Morgado [mailto:aleksander at aleksander.es] 
Sent: Wednesday, March 22, 2017 1:39 AM
To: Jan Graczyk <JanG at nytec.com>
Cc: Dan Williams <dcbw at redhat.com>; modemmanager-devel at lists.freedesktop.org
Subject: Re: [PATCH] serial: allow specifying baudrate to use via udev tags

Hey Jan,

On Tue, Mar 21, 2017 at 11:16 PM, Jan Graczyk <JanG at nytec.com> wrote:
> I have tried running ModemManager with /dev/ttymxc2 port set to 57600 baud rate. It looks like as I can see from ModemManager debug logging the QUECTEL UC20 device is not recognized. I have looked into the ModemManager supported devices website https://www.freedesktop.org/wiki/Software/ModemManager/SupportedDevices/#index2h1 and there is no support for this device. I would need to create a new plugin for this device.

Maybe, or maybe not.

The first step is to have the TTY recognized by ModemManager. If it is an AT port, ModemManager should be able to do basic AT probing there and fallback to the "generic" plugin if it doesn't find any specific plugin.

If baudrate is already 57600bps in the modem, and still isn't recognized, it has to be due to some other reason. Try maybe to run "mmcli -S" after some time, so that a manual re-scan is relaunched (but use ModemManager git master to do so, or it may really not work as I fixed something related to that 2 weeks ago.).

BTW, try not to mix email threads... :)

--
Aleksander
https://aleksander.es