From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] drivers/ata/libata-eh.c: fix unused variable warning Date: Fri, 23 Apr 2010 09:01:04 +0200 Message-ID: <4BD145B0.8080102@kernel.org> References: <1271858846-1706-1-git-send-email-antonf@turbolinux.com.cn> <20100421152404.62699040@lxorguk.ukuu.org.uk> <4BCF1247.8080508@gmail.com> <4BCFA50E.80800@gmail.com> <4BD13E84.2040204@kernel.org> <20100423064332.GA22988@shell.devel.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:47202 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756092Ab0DWHBl (ORCPT ); Fri, 23 Apr 2010 03:01:41 -0400 In-Reply-To: <20100423064332.GA22988@shell.devel.redhat.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Fang Wenqi , linux-ide@vger.kernel.org, Alan Cox , antonf@turbolinux.com.cn Hello, Jeff. On 04/23/2010 08:43 AM, Jeff Garzik wrote: > On Fri, Apr 23, 2010 at 08:30:28AM +0200, Tejun Heo wrote: >> On 04/22/2010 03:23 AM, Fang Wenqi wrote: >>> Sorry that the title should be: >>> "fix uninitialized variable warning" >>> >>> not >>> "fix unused variable warning" >>> >>> Need I re-send the patch mail ? >> >> Yes, please do so. gcc 4.4.1 generates a spurious warning on it too. >> >> Acked-by: Tejun Heo > > It's not a spurious warning. The code failed to fully initialize all > fields of the ata_taskfile structure, prior to copying the ata_taskfile > structure into qc->result_tf. Hmmmm.... right, I've always thought it was gcc not noticing the structure is being initialized in ata_eh_read_log_10h() but it actually is noticing much more, so something like the following is more appropriate? Subject: libata: fully initialize @tf in ata_eh_read_log_10h() ata_eh_read_log_10h() filled @tf only partially. It didn't cause any correctness issues but triggered spruious uninitialized variable warning. Do ata_tf_init() before filling in @tf. Signed-off-by: Tejun Heo --- drivers/ata/libata-eh.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 9f6cfac..fa7e902 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1434,6 +1434,7 @@ static int ata_eh_read_log_10h(struct ata_device *dev, *tag = buf[0] & 0x1f; + ata_tf_init(dev, tf); tf->command = buf[2]; tf->feature = buf[3]; tf->lbal = buf[4];