On 06/28/2012 07:37 AM, Marek Vasut wrote:
Dear Ilya Yanok,
Dear Marek,
28.06.2012 02:48, Marek Vasut wrote:
Sorry for missing this discussion. I think compile-time disabling of the cache is too brutal. ehci-hcd cache handling is broken anyway: doing unaligned flushes/invalidates is a bug, and we know for sure that upper layers don't care about alignment (and I bet ehci-hcd does this even for its internal buffers). So what's the point in all this cache handling in ehci-hcd? It's not going to work anyway and just produces problems. So I suggest to just disable all this stuff until generic code will be fixed. Alternatively we can do bounce-buffering inside driver.
We should rather introduce generic bounce buffer. But the upper layers are getting fixed recently so we should be getting there.
Really? Don't forget my old patch [1] then ;) Still I think we should rip off all the cache stuff from ehci-hcd until all patches for upper layers are included. Again, this stuff doesn't do proper things now anyway and USB won't work with dcache enabled.
Have you tested? I enabled dcache on m28 and tried asix ethernet (needed a patch) and loading from ext2 and vfat (worked).
So then we have more places that accidentially aligned to 32bytes since this does not work on TI parts which require 64byte alignment.