Re: [PATCH 1/6] tty: n_gsm: Add support for serdev drivers

Ivaylo Dimitrov
2024-12-19T08:02:28Z

On 19.12.24 г. 9:53 ч., Jiri Slaby wrote:
> On 19. 12. 24, 8:45, Ivaylo Dimitrov wrote:
>> Hi,
>>
>> ...
>>
>> On 29.11.20 г. 22:51 ч., Pavel Machek wrote:
>>>>
>>>> It looks like you may also have a problem with tty hangups, which
>>>> serdev
>>>> does not support currently. There are multiple paths in n_gsm which can
>>>> trigger a hangup (e.g. based on remote input) and would likely lead
>>>> to a
>>>> crash
>>>
>>> I don't believe we need to support hangups for the Droid 4, but
>>> obviously it would be good not to crash. But I don't know where to
>>> start looking, do you have any hints?
>>>
>>
>> I changed the patch so it calls tty_port_register_device_serdev,
>> ported gnss driver to use serdev_device, got it working:
>>
>> root@devuan-droid4:~# cat /dev/gnss0
>> $GPGGA,,,,,,0,,,,,,,,*66
>> $GNGNS,,,,,,NN,,,,,,*53
>> $GNGNS,,,,,,NN,,,,,,*53
>> $GNGNS,,,,,,NN,,,,,,*53
>> $GPVTG,,T,,M,,N,,K,N*2C
>> $GPRMC,,V,,,,,,,,,,N*53
>> $GPGSA,A,1,,,,,,,,,,,,,,,*1E
>> $GLGSV,1,1,01,255,,,37*52
>> $GPGGA,,,,,,0,,,,,,,,*66
>> $GNGNS,,,,,,NN,,,,,,*53
>> $GNGNS,,,,,,NN,,,,,,*53
>> $GNGNS,,,,,,NN,,,,,,*53
>>
>> However, I get:
>>
>> gsmtty gsmtty4: tty_hangup: tty->count(1) != (#fd's(0) + #kopen's(0))
>>
>> when closing /dev/gnss0
>>
>> Any hint what shall be implemented in serdev to properly handle hangups?
>
> Without code, no.

Which code? The $subject patch with changes I made? or gnss driver? both?

Thanks,
Ivo