From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: Regression with wait_event_timeout in next-20140226
Date: Wed, 26 Feb 2014 17:50:43 +0100
Message-ID: <20140226165043.GA22802@laptop.programming.kicks-ass.net>
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To: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, linux-next@vger.kernel.org, Johannes Berg <johannes.berg@intel.com>, Steven Rostedt <rostedt@goodmis.org>, Andrew Morton <akpm@linux-foundation.org>

On Wed, Feb 26, 2014 at 05:35:19PM +0100, Gregory CLEMENT wrote:
> Hi,
> 
> while testing next-20140226 I got an issue with the function
> wait_event_timeout. When this function timed out instead of returning
> 0, it returned the value of the timeout passed in parameter. I found
> that reverting "sched/wait: Suppress Sparse 'variable shadowing'
> warning" fixed this regression.
> 
> I got this issue in the driver drivers/i2c/busses/i2c-mv64xxx.c.

Ah indeed. We actually rely on the shadowing for ___wait_cond_timeout().

We further used the __ret variable in __wait_event_timeout()'s cmd
argument: __ret = schedule_timeout(__ret). That now explicitly uses the
wrong __ret.

Yeah, we need to pull that patch.