Re: [PATCH 1/2] tty: n_gsm: Fix long delays with control frame timeouts in ADM mode

From: Tony Lindgren
Date: Mon Apr 09 2018 - 09:43:08 EST


* Pavel Machek <pavel@xxxxxx> [180409 10:56]:
> Ok, I should have all that enabled. But droid4-ngsm still fails:
>
> user@devuan:/my/droid4-ngsm$ sudo ./droid4-ngsm
> Starting ngsm..
> Testing ngsm..
> Could not open /dev/gsmtty1: Level 2 halted
> Trying to start ngsm again: Level 2 halted
> Starting ngsm..

I guess you must have phy-mapphone-mdm6600 enabled as you a have
working modem over USB. What do you see in dmesg if you enable n_gsm
debug with modprobe n_gsm debug=0xff or on kernel cmdline?

> commit 984c7706ff180e33096c57183435d925cb644576 says:
>
> ARM: dts: omap4-droid4: Configure uart1 pins
>
> These are needed to use the n_gsm driver for TS 27.010 UART
> multiplexing. Note that support for the OOB wake gpio is still
> missing so the UART is not yet usable for n_gsm.
>
> ...am I still missing the OOB wake gpio support?

We can get away without OOB wake gpio for a while as mdm6600 is not
yet suspended over USB. But if you have manually suspended mdm6600
USB interface via /sys, then it won't respond properly on n_gsm
either.

Regards,

Tony