Hi, On Wed, Sep 12, 2012 at 4:42 PM, Marek Vasut <ma...@denx.de> wrote: > 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.
Yes I agree, and I think it is pretty close - certainly much better than it used to be. The good thing about them being annoying is that they will likely get fixed :-) Regards, Simon >> > >> > 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 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
