Re: [PATCH] serial: imx: cancel RS485 trigger hrtimers in shutdown and remove

[Jiri Slaby <jirislaby@kernel.org>]

On 19. 08. 26, 4:19, Fan Wu wrote:
> The rs485 delay hrtimers trigger_start_tx and trigger_stop_tx are
> embedded in the devm allocated struct imx_port, and their callbacks
> reach the port through container_of() and touch registers under the
> port lock.  Nothing cancels them synchronously: the tx paths only
> call hrtimer_try_to_cancel(), which does not wait for a running
> callback, and the bounded wait in imx_uart_shutdown() can give up,
> force tx_state to OFF, and leave a timer armed.  After
> imx_uart_remove() returns, devm frees the port and a late callback
> dereferences freed memory.
> 
> Cancel both timers at the end of imx_uart_shutdown(), after the port
> lock is dropped and before the clocks are disabled, and again in
> imx_uart_remove() before the devm free:


> serial core does not call the
> driver shutdown on every path that reaches remove().

Could you be more specific on what path it does not?

thanks,
-- 
js
suse labs