2010/10/31 Anand Gadiyar <gadiyar@xxxxxx>: > On 10/27/2010 11:27 AM, Ming Lei wrote: >> I don't think there is better fix in software than the two ones >> you posted. >> > > Looking at old mail threads, I remember Ajay had one objection to using PIO > for unaligned transfers - when multiple DMA channels are repeatedly hit with > unaligned DMA addresses, throughput and CPU load go for a toss. Ajay wanted > to use the OMAP's SystemDMA engine to carry out the transfers in those > cases. Anyway, that's a separate topic - and should probably be done after > the DMA code is rewritten. (I think Felipe had some plans for that). Seems DMA code should not be rewritten, only a DMA version of musb_write_fifo and musb_read_fifo need to be implemented as omap dependent code just like Blackfin, right? > > I've posted a patch implementing the quick fix. Let me know if it solves the > problem with g_ether. Yes, I have tested your patch about g_ether on beagle xM, and it does fix the DMA issue for unaligned buffer address. > > While fixing this, I noticed dma_channel_program also returns "true" > while it is supposed to return an "int". Topic for a separate patch. > > - Anand > -- Lei Ming -- 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
