From mboxrd@z Thu Jan 1 00:00:00 1970 From: vinod.koul@intel.com (Vinod Koul) Date: Fri, 17 Oct 2014 13:02:26 +0530 Subject: [PATCH v6 1/3] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver In-Reply-To: <20141017065357.GE2367@ldesroches-Latitude-E6320> References: <1412175565-810-1-git-send-email-ludovic.desroches@atmel.com> <1412175565-810-2-git-send-email-ludovic.desroches@atmel.com> <20141015133004.GP1638@intel.com> <20141016141048.GC2367@ldesroches-Latitude-E6320> <20141016161233.GJ1638@intel.com> <20141017065357.GE2367@ldesroches-Latitude-E6320> Message-ID: <20141017073226.GM1638@intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Oct 17, 2014 at 08:53:57AM +0200, Ludovic Desroches wrote: > > > > > > For memcpy why should we need slave_config. The system memory source and > > > > destination width could be assumed to relastic values and then burst sizes > > > > maxed for performance. These values make more sense for periphral where we > > > > have to match up with the periphral > > > > > > I don't tell I need slave_config. We have already talked about this. I don't > > > see the problem. It is only a comment, a reminder. The only information > > > I may need, one day, is the direction because we have to set src and dst > > > interfaces. At the moment, all our products are done in a way nand flash > > > and DDR are on the same interface so we don't have to care about > > > direction. > > > Since we don't have the direction, two solutions: > > > - remember this limitation for next products, that's why there is this reminder, > > > - change our nand driver in order to see nand as a peripheral instead of > > > a memory. > > I think treating NAND as memory may not be a right model. It should be > > treated as periphral with incrementing and decrementing address value. That > > way you should be able to set the right properties for it. > > > > The system memory copy is right model for memcpy. > > Ok, I'll discuss of it with the atmel nand maintener. Even if there is > something to improve here, I hope it is not considered as a blocking point > to get the xdmac driver included into 3.19 because at the moment we have no > DMA on the SAMA5D4 recently introduced. That sounds good to me, no this is non blocker here And yes keeping the comment here is fine to warn folks. -- ~Vinod