From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757513Ab2CMHK6 (ORCPT ); Tue, 13 Mar 2012 03:10:58 -0400 Received: from mprc.pku.edu.cn ([162.105.203.9]:35847 "EHLO mprc.pku.edu.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755926Ab2CMHK4 (ORCPT ); Tue, 13 Mar 2012 03:10:56 -0400 Message-ID: <1331622633.2048.87.camel@epip-laptop> Subject: Re: [PATCH 7/7] arch/unicore32/kernel/dma.c: ensure arguments to request_irq and free_irq are compatible From: Guan Xuetao Reply-To: gxt@mprc.pku.edu.cn To: Julia Lawall Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 13 Mar 2012 15:10:33 +0800 In-Reply-To: References: <1331494587-12196-1-git-send-email-Julia.Lawall@lip6.fr> <1331494587-12196-8-git-send-email-Julia.Lawall@lip6.fr> <1331513926.2048.58.camel@epip-laptop> Organization: MPRC, PKU Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2012-03-12 at 06:27 +0100, Julia Lawall wrote: > On Mon, 12 Mar 2012, Guan Xuetao wrote: > > > On Sun, 2012-03-11 at 20:36 +0100, Julia Lawall wrote: > >> From: Julia Lawall > >> > >> Convert calls to free_irq so that the second argument is the same as the > >> last argument of the corresponding call to request_irq, rather than the > >> second to last. Without this property, free_irq does nothing. > >> > >> Signed-off-by: Julia Lawall > >> > >> --- > >> arch/unicore32/kernel/dma.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/arch/unicore32/kernel/dma.c b/arch/unicore32/kernel/dma.c > >> index ae441bc..c813fec 100644 > >> --- a/arch/unicore32/kernel/dma.c > >> +++ b/arch/unicore32/kernel/dma.c > >> @@ -173,7 +173,7 @@ int __init puv3_init_dma(void) > >> ret = request_irq(IRQ_DMAERR, dma_err_handler, 0, "DMAERR", NULL); > >> if (ret) { > >> printk(KERN_CRIT "Can't register IRQ for DMAERR\n"); > >> - free_irq(IRQ_DMA, "DMA"); > >> + free_irq(IRQ_DMA, NULL); > >> return ret; > >> } > >> > > Yeah, it's an obvious mistake. Thanks. > > Because the dma device is just located inside PKUnity-3 SoC, and > > request_irq() should always return 0, I prefer to remove this free_irq() > > line. > > Remove the whole if test I guess. Is there a nce way to indicate that the > return value is not needed (eg for the benefit of future bug finding > rules)? > > julia In this case, removing the line containing free_irq() is well enough, because IRQ_DMA can work even when IRQ_DMAERR doesn't work. And we need printk and error return value to get potential logical bug information. Thanks & Regards, Guan Xuetao