Re: [PATCH 1/2] tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown

From: Akash Asthana
Date: Tue Mar 17 2020 - 09:05:59 EST



On 3/14/2020 2:16 AM, Douglas Anderson wrote:
On a board using qcom_geni_serial I found that I could no longer
interact with kdb if I got a crash after the "agetty" running on the
same serial port was killed. This meant that various classes of
crashes that happened at reboot time were undebuggable.

Reading through the code, I couldn't figure out why qcom_geni_serial
felt the need to run so much code at port shutdown time. All we need
to do is disable the interrupt.

After I make this change then a hardcoded kgdb_breakpoint in some late
shutdown code now allows me to interact with the debugger. I also
could freely close / re-open the port without problems.

Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Looks good to me.

Reviewed-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project