From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755110AbbHYII0 (ORCPT ); Tue, 25 Aug 2015 04:08:26 -0400 Received: from www.linutronix.de ([62.245.132.108]:49888 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752358AbbHYIIW (ORCPT ); Tue, 25 Aug 2015 04:08:22 -0400 Date: Tue, 25 Aug 2015 10:07:46 +0200 (CEST) From: Thomas Gleixner To: yalin wang cc: vinod.koul@intel.com, dan.j.williams@intel.com, robh@kernel.org, jiang.liu@linux.intel.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dma/ipu: change ipu_irq_handler() to remove compile warning In-Reply-To: <1440489668-3139-1-git-send-email-yalin.wang2010@gmail.com> Message-ID: References: <1440489668-3139-1-git-send-email-yalin.wang2010@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Aug 2015, yalin wang wrote: > Change ipu_irq_handler() to avoid gcc warning: > > drivers/dma/ipu/ipu_irq.c:305:4: warning: 'irq' may be used > uninitialized in this function [-Wmaybe-uninitialized] > generic_handle_irq(irq); That's a false positive from GCC. irq is always initialized when generic_handle_irq() is called. > Signed-off-by: yalin wang > --- > drivers/dma/ipu/ipu_irq.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/dma/ipu/ipu_irq.c b/drivers/dma/ipu/ipu_irq.c > index 7489d2a..1a74eee 100644 > --- a/drivers/dma/ipu/ipu_irq.c > +++ b/drivers/dma/ipu/ipu_irq.c > @@ -286,23 +286,21 @@ static void ipu_irq_handler(unsigned int __irq, struct irq_desc *desc) > raw_spin_unlock(&bank_lock); > while ((line = ffs(status))) { > struct ipu_irq_map *map; > - unsigned int irq; > > line--; > status &= ~(1UL << line); > > raw_spin_lock(&bank_lock); > map = src2map(32 * i + line); > - if (map) > - irq = map->irq; > raw_spin_unlock(&bank_lock); > > if (!map) { > pr_err("IPU: Interrupt on unmapped source %u bank %d\n", > line, i); > continue; > + } else { > + generic_handle_irq(map->irq); So you change that from retrieving the irq number with bank lock held to an unprotected access. Thanks, tglx