linux-kernel - Re: [PATCH] serdev: Restore serdev_device_write

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Message-ID: <20170502090638.GB2973@localhost>
Date:   Tue, 2 May 2017 11:06:38 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Stefan Wahren <stefan.wahren@...e.com>
Cc:     Rob Herring <robh@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>,
        Sebastian Reichel <sre@...nel.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Andrey Smirnov <andrew.smirnov@...il.com>,
        linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] serdev: Restore serdev_device_write_buf for atomic
 context

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).

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

> Signed-off-by: Stefan Wahren <stefan.wahren@...e.com>
> Fixes: 6fe729c4bdae ("serdev: Add serdev_device_write subroutine")

Reviewed-by: Johan Hovold <johan@...nel.org>

Thanks,
Johan