On Monday, August 22, 2011 06:42:06 PM Anton Staaf wrote: > On Mon, Aug 22, 2011 at 9:08 AM, Mike Frysinger <vap...@gentoo.org> wrote: > > On Monday, August 22, 2011 03:29:52 Lukasz Majewski wrote: > >> On Fri, 19 Aug 2011 11:35:50 -0400 Mike Frysinger wrote: > >> > On Friday, August 19, 2011 11:28:18 Lukasz Majewski wrote: > >> > > On Fri, 19 Aug 2011 09:57:10 -0400 Mike Frysinger wrote: > >> > > > On Friday, August 19, 2011 05:25:13 Lukasz Majewski wrote: > >> > > > also, what is the code size increase with your patch ? > >> > > > >> > > Code size overhead (s5p_goni target): > >> > > Without proposed changes: 167928 B (u-boot.bin) > >> > > With changes: 168208 B (u-boot.bin) > >> > > > >> > > Delta: 280 B > >> > > >> > np if it gives significant (more than system noise) speedups. any > >> > details on that ? > >> > >> No tests performed yet. The goal of those patches is to preserve the > >> MMC subsystem functionality when dcache is enabled (the ext_csd[512] > >> corruption is observed with d-cache enabled). > > > > so you're papering over a bug in some controller's cache handling ? > > shouldnt you fix the controller in question by having it flush its > > caches ? aligning random buffers to make cache issues "go away" isnt > > the right way for anything. -mike > > No, this isn't something that can be fixed in the controller driver > code. This is a fundamental problem with buffers in U-Boot that needs > to be resolved by aligning all buffers used for DMA. The main problem > is that invalidating a non-cache line aligned buffer is not a safe > operation. There have been a number of threads discussing this. The > general consensus was to make attempting to invalidate an unaligned > buffer an error and then to clean up the unaligned buffers as we find > them. > > Lukasz, I also have been using memalign to clean up accesses in local > patches, so you've got my vote there. I am curious as to whether we > should provide a single block allocation API or if each subsection > should add lazy memalign allocations to create aligned buffers when > they are needed...
Maybe some dma_allocate_aligned() would be cool. And probably control the alignment with some #define CONFIG PLATFORM_ALIGNMENT_SIZE ? Cheers > > Thanks, > Anton > > > _______________________________________________ > > U-Boot mailing list > > U-Boot@lists.denx.de > > http://lists.denx.de/mailman/listinfo/u-boot > > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
