On Thu, 5 Aug 2010, Santosh Shilimkar wrote: > This patch fixes the issue which was observed while transfering > a large file ( > 20MB) over USB (OMAP MUSB controller acts as USB host) > to an attached USB thumb drive. > > It was found that CDB field of CBW packet was set to 0x0. This was > due to missing a barrier before DMA engine starts transfer. > This buffer is allocated using dma_alloc_coherent which gives > non-cacheble but bufferable memory and hence needed a write > memory barrier to flush the write buffer. If you see this problem when the controller uses DMA acting as a host, does this mean the same problem might occur when it uses DMA acting as a peripheral? Alan Stern -- 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
