Re: [PATCH] serial: 8250: Fix oops for port->pm on uart_change_pm()

[Andy Shevchenko]

On Fri, Aug 04, 2023 at 04:15:51PM +0300, Tony Lindgren wrote:
> Unloading a hardware specific 8250 driver can produce error "Unable to
> handle kernel paging request at virtual address" about ten seconds after
> unloading the driver. This happens on uart_hangup() calling
> uart_change_pm().
> 
> Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port
> specific driver unbind") was only a partial fix. If the hardware specific
> driver has initialized port->pm function, we need to clear port->pm too.
> Just reinitializing port->ops does not do this. Otherwise serial8250_pm()
> will call port->pm() instead of serial8250_do_pm().

Oh, good catch!
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>

-- 
With Best Regards,
Andy Shevchenko