Am Dienstag, 16. Februar 2010 08:57:53 schrieb Shilimkar, Santosh: > Continuing on the USB issue w.r.t cache coherency, the usb host > code is violating the buffer ownership rules of streaming APIs from > dma and non-dma transfers point if view. > > We have a below temporary patch to get around the issue and probably it > needs to be fixed in the right way in the stack because some controllers > may not have PIO option even for control transfers. (e.g. Synopsis EHCI > controller) This seems wrong to me. Buffers for control transfers may be transfered by DMA, so the caches must be flushed on architectures whose caches are not coherent with respect to DMA. Would you care to elaborate on the exact nature of the bug you are fixing? Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
