From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 5/5] spi: fix return value check in hspi_probe(). Date: Fri, 11 Jan 2013 15:02:02 +0000 Message-ID: <20130111150202.C25583E08C3@localhost> References: <1355271894-5284-1-git-send-email-tipecaml@gmail.com> <1355271894-5284-6-git-send-email-tipecaml@gmail.com> <87txrsqf7f.wl%kuninori.morimoto.gx@renesas.com> <20121219151154.937EC3E0AD7@localhost> <20121219163914.GN5032@mwanda> <20121222095620.83E243E07FA@localhost> <20130103160455.GO7247@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Cyril Roelandt , Kuninori Morimoto , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dan Carpenter Return-path: In-Reply-To: <20130103160455.GO7247@mwanda> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Thu, 3 Jan 2013 19:04:55 +0300, Dan Carpenter wrote: > On Sat, Dec 22, 2012 at 09:56:20AM +0000, Grant Likely wrote: > > On Wed, 19 Dec 2012 19:39:14 +0300, Dan Carpenter wrote: > > > On Wed, Dec 19, 2012 at 03:11:54PM +0000, Grant Likely wrote: > > > > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto wrote: > > > > > > > > > > Hi > > > > > > > > > > > According to its documentation, clk_get() returns a "valid IS_ERR() condition > > > > > > containing errno", so we should call IS_ERR() rather than a NULL check. > > > > > > > > > > > > Signed-off-by: Cyril Roelandt > > > > > > > > > > Acked-by: Kuninori Morimoto > > > > > > > > Applied, thanks. > > > > > > In another thread, we were just talking about who clk_get() can > > > return a NULL if !CONFIG_HAVE_CLK. That might change to match the > > > documentation later... Not sure. > > > > So what is the solution here? Will the dummy clk_get() be changed, or is > > there more work needed on the drivers? > > > > This driver can't function without a clk. It should select that at > build time instead of testing for it at probe. Just checking for > IS_ERR() will NOT cause a NULL dereference so the patch is ok in > that respect. I'm not sure if this can be build without > CONFIG_HAVE_CLK. Your suggestion is to make this driver depend on CONFIG_HAVE_CLK? I'm fine with that, but it doesn't sort out the core infrastructure question about whether it is valid for the empty clk_get() to return NULL. Nor is it a particularly sustainable solution (ie. if a large number of drivers want to do the same thing). g. ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812