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

[Marek Vasut]

Dear Ilya Yanok,

> Hi,
> 
> 21.06.2012 02:14, Tom Rini wrote:
> > USB EHCI and DCACHE are not compatible, so disable DCACHE support at
> > build-time as run-time disable is insufficient for USB use.
> 
> 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.

> 
> Regards, Ilya.

Best regards,
Marek Vasut