From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754717Ab3ELQjo (ORCPT ); Sun, 12 May 2013 12:39:44 -0400 Received: from mga09.intel.com ([134.134.136.24]:3087 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754293Ab3ELQjn (ORCPT ); Sun, 12 May 2013 12:39:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,657,1363158000"; d="scan'208";a="332875451" Date: Sun, 12 May 2013 21:34:40 +0530 From: Vinod Koul To: Stephen Warren Cc: Wolfram Sang , linux-kernel@vger.kernel.org, Dan Williams , linux-tegra@vger.kernel.org Subject: Re: [RFC 04/42] drivers/dma: don't check resource with devm_ioremap_resource Message-ID: <20130512160440.GA27639@intel.com> References: <1368173847-5661-1-git-send-email-wsa@the-dreams.de> <1368173847-5661-5-git-send-email-wsa@the-dreams.de> <518D21D4.6000609@wwwdotorg.org> <20130510175739.GA2912@katana> <518D49B0.4050901@wwwdotorg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <518D49B0.4050901@wwwdotorg.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 10, 2013 at 01:25:36PM -0600, Stephen Warren wrote: > On 05/10/2013 11:57 AM, Wolfram Sang wrote: > > On Fri, May 10, 2013 at 10:35:32AM -0600, Stephen Warren wrote: > >> On 05/10/2013 02:16 AM, Wolfram Sang wrote: > >>> devm_ioremap_resource does sanity checks on the given resource. No need to > >>> duplicate this in the driver. > >> > >>> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c > >> > >>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > >>> - if (!res) { > >>> - dev_err(&pdev->dev, "No mem resource for DMA\n"); > >>> - return -EINVAL; > >>> - } > >>> - > >>> tdma->base_addr = devm_ioremap_resource(&pdev->dev, res); > >> > >> One issue here is that it's not obvious just from reading the code > >> that's left behind that the "missing" error-checking of the > >> platform_get_resource() return value is OK because > >> devm_ioremap_resource() will check it "for us". Everyone now has to > >> mentally maintain a list of exceptions where it's OK not to error-check. > > > > My goal is to make not-checking the standard case with devm. > > OK, if no parameters passed to any devm function every need to be > error-checked, that'll certainly be a bit easier to remember. Okay to remove the log message and move to devm_ but I dont agree with this patch not returning error above. We shouldnt supress the error.. -- ~Vinod