linux-kernel - Re: [PATCH] DRM: Armada: fixup wait_event

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Date:	Wed, 10 Jun 2015 12:22:36 +0100
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Nicholas Mc Guire <hofrat@...dl.org>
Cc:	David Airlie <airlied@...ux.ie>, dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] DRM: Armada: fixup wait_event_timeout being ignored

On Wed, Jun 10, 2015 at 01:07:08PM +0200, Nicholas Mc Guire wrote:
> The calling side seems to assume 0 as success and <0 as error so 
> returning -ETIME should be fine here.

The idea here is to allow the remainder of the code to execute when
the condition succeeds _or_ times out.  If it times out, that is
not a failure - it merely means that the display has been blanked
and we're not seeing frame done interrupts anymore.

The code should not be checking the returned value at all - in fact
I have updates to this code which (in part) remove this, and fix a
glaring problem that the wait queue is never woken.

I wonder how many places you've made this same mistake... please
ensure that you review the code you're changing carefully.

-- 
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according to speedtest.net.
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