Dear Stephen Warren, > On 09/12/2012 04:38 PM, Marek Vasut wrote: > > Dear Stephen Warren, > > > >> On 09/12/2012 10:19 AM, Tom Warren wrote: > >>> Folks, > >>> > >>> Stephen Warren has posted an internal bug regarding the cache > >>> alignment 'warnings' seen on Tegra20 boards when accessing MMC. Here's > >>> the gist: > >>> > >>> Executing "mmc dev 0" still yields cache warnings: > >>> > >>> Tegra20 (Harmony) # mmc dev 0 > >>> ERROR: v7_dcache_inval_range- stop address is not aligned- 0x3fb69908 > >>> mmc0 is current device > >> > >> ... > >> > >>> There have been patches in the past (IIRC) that have tried to ensure > >>> all callers (FS, MMC driver, USB driver, etc.) force their buffers to > >>> the appropriate alignment, but I don't know that we can ever correct > >>> every instance, now or in the future. > >>> > >>> Can we start a discussion about what we can do about this warning? > >>> Adding an appropriate #ifdef (CONFIG_SYS_NO_CACHE_ALIGNMENT_WARNINGS, > >>> etc.) where Stephen put his #if 0's would be one approach, or changing > >>> the printf() to a debug(), perhaps. As far as I can tell, these > >>> alignment 'errors' don't seem to produce bad data in the transfer. > >> > >> I don't think simply turning off the warning is the correct approach; I > >> believe they represent real problems that can in fact cause data > >> corruption. I don't believe we have any choice other than to fully solve > >> the root-cause. > > > > Try CONFIG_MMC_BOUNCE_BUFFER or what it was called ... see > > inclued/configs/m28evk.h , I use it there. > > That didn't seem to change anything. > > I just re-tested and it looks like there's one single instance of this > cache warning now when running "mmc dev 0"; there used to be hundreds of > them when loading files from eMMC. Perhaps it depends on some runtime > allocation or something though, and I'm just getting lucky and seeing > fewer of them.
Yes it does, internal unaligned variables passed through to the MMC driver ... the bounce buffer should fix that up for you. Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
