[U-Boot] [PATCH v4 3/6] mcx: Disable DCACHE since USB EHCI is enabled

Ilya Yanok
2012-06-28T13:57:53Z

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.

BTW, I think this was under #ifdef CONFIG_EHCI_DCACHE last time looked
at it. Was this changed by your commit? I think that's the source of the
problem this series tries to address: you've taken buggy code out of
#ifdef ;) I think it's better to just put it back until upper layers
won't be fixed.

Regards, Ilya.

[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/114235