Hi,
On Tue, Oct 1, 2024 at 5:51 AM Johan Hovold johan+linaro@kernel.org wrote:
A commit adding back the stopping of tx on port shutdown failed to add back the locking which had also been removed by commit e83766334f96 ("tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown").
Hmmm, when I look at that commit it makes me think that the problem that commit e83766334f96 ("tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown") was fixing was re-introduced by commit d8aca2f96813 ("tty: serial: qcom-geni-serial: stop operations in progress at shutdown"). ...and indeed, it was. :(
I can't interact with kgdb if I do this:
1. ssh over to DUT 2. Kill the console process (on ChromeOS stop console-ttyMSM0) 3. Drop in the debugger (echo g > /proc/sysrq-trigger)
This bug predates your series, but since it touches the same code maybe you could fix it at the same time? I will note that commit e83766334f96 ("tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown") mentions that it wasn't required for FIFO mode--only DMA...
Aside from the pre-existing bug, I agree that the locking should be there.
-Doug