From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Date: Tue, 29 Jul 2008 13:07:45 +0000 Subject: Re: [patch] IA64: only call up() in salinfo_work_to_do() if Message-Id: <20080729130742.GA20158@verge.net.au> List-Id: References: <20080729094718.GA5247@verge.net.au> <1163.1217335629@ocs10w> In-Reply-To: <1163.1217335629@ocs10w> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Keith Owens Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Tony Luck On Tue, Jul 29, 2008 at 10:47:09PM +1000, Keith Owens wrote: > Simon Horman (on Tue, 29 Jul 2008 19:47:20 +1000) wrote: > >Aesthetic issues aside is it safe to call up() if down_trylock() failed? > > > >arch/ia64/kernel/salinfo.c: In function `salinfo_work_to_do': > >arch/ia64/kernel/salinfo.c:195: warning: ignoring return value of `down_trylock' > > > >Signed-off-by: Simon Horman > > > >Index: linux-2.6/arch/ia64/kernel/salinfo.c > >=================================> >--- linux-2.6.orig/arch/ia64/kernel/salinfo.c 2008-07-29 19:06:33.000000000 +1000 > >+++ linux-2.6/arch/ia64/kernel/salinfo.c 2008-07-29 19:40:02.000000000 +1000 > >@@ -192,8 +192,8 @@ struct salinfo_platform_oemdata_parms { > > static void > > salinfo_work_to_do(struct salinfo_data *data) > > { > >- down_trylock(&data->mutex); > >- up(&data->mutex); > >+ if (down_trylock(&data->mutex) = 0) > >+ up(&data->mutex); > > } > > > > static void > > NAK. The whole point of this function is to set the mutex to the up > state, irrespective of whether it was already down or not. Tracking > the state of data->mutex in all the possible contexts is just too > fragile, especially since it can be modified from NMI context. > salinfo_work_to_do() ensures that the mtuex ends in the up state. > > To remove the warning, just stick '(void)' in front of down_trylock(). Thanks, will do. -- Horms