Re: [V3] drivers/tty/serial/qcom-geni-serial: Do stop_rx in suspend path for console if console_suspend is disabled

[Vijaya Krishna Nivarthi]

On 4/7/2022 1:21 PM, Jiri Slaby wrote:
> On 07. 04. 22, 9:25, Vijaya Krishna Nivarthi wrote:
> > For the case of console_suspend disabled, if back to back suspend/resume
> > test is executed, at the end of test, sometimes console would appear to
> > be frozen not responding to input. This would happen because, for
> > console_suspend disabled, suspend/resume routines only turn resources
> > off/on but don't do a port close/open.
> > As a result, during resume, some rx transactions come in before 
> > system is
> > ready, malfunction of rx happens in turn resulting in console appearing
> > to be stuck.
> >
> > Do a stop_rx in suspend sequence to prevent this. start_rx is already
> > present in resume sequence as part of call to set_termios which does a
> > stop_rx/start_rx.
>
> So why is it OK for every other driver? Should uart_suspend_port() be 
> fixed instead?

For qcom driver we know that set_termios() call in uart_suspend_port() 
will recover with a call to start_rx.
However that may not be the case with other drivers.

We can move stop_rx to uart_suspend_port() and additionally have a 
start_rx in uart_resume_port()
Please let know if such a change would be ok.
Thank you.