tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown
authorDouglas Anderson <dianders@chromium.org>
Fri, 13 Mar 2020 20:46:51 +0000 (13:46 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 14 Mar 2020 08:40:27 +0000 (09:40 +0100)
commite83766334f96b3396a71c7baa3b0b53dfd5190cd
treeb8b98ef50e6ffb93075097f76d3464e8c60bf7ef
parent1aa6e058dd6cd04471b1f21298270014daf48ac9
tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown

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@chromium.org>
Link: https://lore.kernel.org/r/20200313134635.1.Icf54c533065306b02b880c46dfd401d8db34e213@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/qcom_geni_serial.c