From: robert.jarzmik@free.fr (Robert Jarzmik) Date: Sat, 10 Aug 2013 00:50:15 +0200 Subject: [PATCH 00/20] ARM: pxa: move core and drivers to dmaengine In-Reply-To: <1375889649-14638-1-git-send-email-zonque@gmail.com> (Daniel Mack's message of "Wed, 7 Aug 2013 17:33:49 +0200") References: <1375889649-14638-1-git-send-email-zonque@gmail.com> Message-ID: <87zjsqzdg8.fsf@free.fr> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Daniel Mack writes: > * camera driver: > I started the transition, but I'm not sure how much sense that > makes without access to the hardware. I'd much appreciate if > anyone could volunteer for this piece; I'll happily share what > I got so far. Sascha, Sachin, Guennadi? Hi Daniel, Do you mean this driver ? : drivers/media/platform/soc_camera/pxa_camera.c In that case I might help. But before I can do that, I have to be convinced that dmaengine can deal with this driver. I'm thinking in particular of : - "hot running DMA" queuing - multiple DMA channel synchronization (ie. 3 channel sync) All that is described in there : Documentation/video4linux/pxa_camera.txt If someone with dmaengine knowledge could have a look at pxa_camera.txt (maybe Vinod ?) and tell me that dma_engine framework fullfills the 2 requirements, then I'll be happy to help. One minor point though is that I'm working on pxa27x. If the serie is not compatible in a way with pxa27x, I won't be able to do anything. Another point I'd like to know, is what is the performance penalty in using dmaengine, and do you have any figures ? Lastly, they was debug information to debug descriptors chaining, channel statuses, requestors. I didn't see where these had gone, could you point me to the right file ? Cheers. -- Robert