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

Ilya Yanok yanok at emcraft.com
Thu Jun 28 00:28:29 CEST 2012


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.

Regards, Ilya.



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