From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp07.smtpout.orange.fr ([80.12.242.129] helo=smtp.smtpout.orange.fr) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V7vWI-0002Xn-DU for linux-mtd@lists.infradead.org; Fri, 09 Aug 2013 22:50:55 +0000 From: Robert Jarzmik To: Daniel Mack Subject: Re: [PATCH 00/20] ARM: pxa: move core and drivers to dmaengine References: <1375889649-14638-1-git-send-email-zonque@gmail.com> Date: Sat, 10 Aug 2013 00:50:15 +0200 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") Message-ID: <87zjsqzdg8.fsf@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: mark.rutland@arm.com, s.neumann@raumfeld.com, linux-mtd@lists.infradead.org, haojian.zhuang@linaro.org, cxie4@marvell.com, lars@metafoo.de, nico@linaro.org, vinod.koul@intel.com, marek.vasut@gmail.com, ezequiel.garcia@free-electrons.com, rmk+kernel@arm.linux.org.uk, devicetree@vger.kernel.org, samuel@sortiz.org, arnd@arndb.de, broonie@kernel.org, mika.westerberg@linux.intel.com, linux-arm-kernel@lists.infradead.org, thomas.petazzoni@free-electrons.com, eric.y.miao@gmail.com, gregkh@linuxfoundation.org, davem@davemloft.net, sachin.kamat@linaro.org, kernel@pengutronix.de, djbw@fb.com, g.liakhovetski@gmx.de List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 From mboxrd@z Thu Jan 1 00:00:00 1970 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