From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [06/10,V2] spi: Add SPI driver for mx233/mx28 Date: Tue, 31 Jul 2012 20:35:59 -0700 Message-ID: <20120801033559.GB2323@roeck-us.net> References: <1341555449-17507-6-git-send-email-marex@denx.de> <20120731205300.GA25721@roeck-us.net> <201208010431.04399.marex@denx.de> <20120801035333.GB1672@S2100-06.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marek Vasut , Fabio Estevam , Wolfgang Denk , Detlev Zundel , Rob Herring , Stefano Babic , spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Chris Ball , Dong Aisheng , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Shawn Guo Return-path: Content-Disposition: inline In-Reply-To: <20120801035333.GB1672-+NayF8gZjK2ctlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org> 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 Wed, Aug 01, 2012 at 11:53:36AM +0800, Shawn Guo wrote: > On Wed, Aug 01, 2012 at 04:31:04AM +0200, Marek Vasut wrote: > > > Couple of reasons for asking: No other SPI master driver calls it in the > > > remove function (unless I missed it), most drivers don't call it in the > > > probe function error path, and if I call it in the remove function in a > > > SPI master driver I am working on, and load/unload the module several > > > times in a row, I get a nasty kernel crash. > > > > It seems the spi_master class takes care of that kfree() in > > spi.c:spi_master_release() . Good catch, thanks! > > > I do not hardware setup to confirm that right away. When > spi_master_release will be called exactly? The time that > spi_master_put gets called? I'm trying to understand if the kfree > is not needed only in remove function, or both probe and remove. > I think the call to spi_master_put() triggers the call to spi_master_release(). If so, kfree() would not be needed at all, and the documentation is wrong. Thanks, Guenter ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/