Re: [PATCH] serdev: Restore serdev_device_write_buf for atomic context

From: Rob Herring
Date: Tue May 02 2017 - 08:42:02 EST

On Tue, May 2, 2017 at 4:06 AM, Johan Hovold <johan@xxxxxxxxxx> wrote:
> On Fri, Apr 28, 2017 at 01:47:21PM +0200, Stefan Wahren wrote:
>> Starting with commit 6fe729c4bdae ("serdev: Add serdev_device_write
>> subroutine") the function serdev_device_write_buf cannot be used in
>> atomic context anymore (mutex_lock is sleeping). So restore the old
>> behavior.
> Yeah, preventing use in atomic context seems unnecessary, although any
> clients writing must now deal with serialisation themselves (as before,
> and as they should).

We could just remove the mutex for serdev_device_write and always make
the client responsible for serialization.

> Calling wait_for_completion in the non-blocking case was also needlessly
> inefficient.

It won't be called because count should be 0.