Dear Thierry Reding, > On Fri, Sep 14, 2012 at 08:53:32AM -0700, Simon Glass wrote: > > 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 :-) > > I think I traced this to the copying of CSD a while back. The problem is > that the transferred buffer is 8 bytes, so there's no way to make it > aligned properly. Unfortunately the entailing discussion did not yield a > solution at the time.
And how exactly does the MMC bounce buffer not help here? > Thierry Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot