> > dma_unmap_single is needed for bounce_buffer. > Yes and it is still done as before (because urb->transfer_dma is the mapped version of bounce_buffer in this case), the patch to unmap_urb_for_dma just copies the bounce buffer back to the transfer_buffer expected by the driver and kfrees the bounce buffer. >> > Suppose hcd->driver->dma_align_shift is zero and HC is byte aligned DMA > enabled, this means DMA is doable between byte aligned memory and HC, > but this does __not__ mean it is safe to do dma mapping or unmapping between > CPU and byte aligned memory, which may cause sync issues between memory > and CPU cache. > > So seems the idea behind the patch is not correct, IMHO. > if dma_align_shift is zero this patch changes nothing. If there are the problems you describe they were there before and a separate issue to the one this patch addresses IMHO. Regards, Martin -- 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
