From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760822AbZBYWjR (ORCPT ); Wed, 25 Feb 2009 17:39:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754119AbZBYWjB (ORCPT ); Wed, 25 Feb 2009 17:39:01 -0500 Received: from mga01.intel.com ([192.55.52.88]:13033 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209AbZBYWjA (ORCPT ); Wed, 25 Feb 2009 17:39:00 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,266,1233561600"; d="scan'208";a="668544855" Subject: Re: [PATCH] fsldma: dev_err 1 too early. From: Dan Williams To: Roel Kluin Cc: lkml , Andrew Morton In-Reply-To: <49A53DCA.4060004@gmail.com> References: <49A53DCA.4060004@gmail.com> Content-Type: text/plain Date: Wed, 25 Feb 2009 15:38:58 -0700 Message-Id: <1235601538.21542.10.camel@dwillia2-linux.ch.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 (2.22.3.1-1.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2009-02-25 at 05:47 -0700, Roel Kluin wrote: > If unsuccessful, i reaches 101 after the loop, so 100 is still success. > > Signed-off-by: Roel Kluin > --- > diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c > index 70126a6..444c4e4 100644 > --- a/drivers/dma/fsldma.c > +++ b/drivers/dma/fsldma.c > @@ -168,7 +168,7 @@ static void dma_halt(struct fsl_dma_chan *fsl_chan) > > while (!dma_is_idle(fsl_chan) && (i++ < 100)) > udelay(10); > - if (i >= 100 && !dma_is_idle(fsl_chan)) > + if (i > 100 && !dma_is_idle(fsl_chan)) > dev_err(fsl_chan->dev, "DMA halt timeout!\n"); > } > Thanks for the report. I prefer a more canonical loop. Objections? -- Dan <----- fsldma: fix off by one in dma_halt From: Dan Williams Prevent dev_err from firing even if we successfully detected 'dma-idle' before the full 1ms timeout has elapsed. Reported-by: Roel Kluin Signed-off-by: Dan Williams --- drivers/dma/fsldma.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 70126a6..86d6da4 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -158,7 +158,8 @@ static void dma_start(struct fsl_dma_chan *fsl_chan) static void dma_halt(struct fsl_dma_chan *fsl_chan) { - int i = 0; + int i; + DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) | FSL_DMA_MR_CA, 32); @@ -166,8 +167,11 @@ static void dma_halt(struct fsl_dma_chan *fsl_chan) DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) & ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA), 32); - while (!dma_is_idle(fsl_chan) && (i++ < 100)) + for (i = 0; i < 100; i++) { + if (dma_is_idle(fsl_chan)) + break; udelay(10); + } if (i >= 100 && !dma_is_idle(fsl_chan)) dev_err(fsl_chan->dev, "DMA halt timeout!\n"); }