From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Tue, 9 Apr 2013 20:09:16 +0100 Subject: [PATCH 5/8] dmaengine: ste_dma40: Ensure src and dst registers are configured correctly In-Reply-To: <201304092057.29684.arnd@arndb.de> References: <1365532783-27425-1-git-send-email-lee.jones@linaro.org> <1365532783-27425-5-git-send-email-lee.jones@linaro.org> <201304092057.29684.arnd@arndb.de> Message-ID: <20130409190916.GF25316@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 09 Apr 2013, Arnd Bergmann wrote: > On Tuesday 09 April 2013, Lee Jones wrote: > > Confusingly d40_log_cfg() is used to set up the logical channel > > configuration registers, but d40_phy_cfg() is used to configure > > physical and logical registers, so it should be called in both > > cases. It is the function call's final attribute which determines > > whether it's a physical or logical channel, not whether the > > function is called or not. > > So how did it ever work? Your description sounds like it was > broken all along, but I would assume that someone tested the code. >>From what I can see, not. My best guess is that the 'test' was to see if the configuration changed using the debug print at the end of the function. I don't see how else the configuration can be written to hardware. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog