> From: Aaro Koskinen [mailto:aaro.koskinen@xxxxxx] > Sent: Sunday, August 18, 2013 4:41 AM > > On Sat, Aug 17, 2013 at 08:44:18PM +0000, Paul Zimmerman wrote: > > > It doesn't get very far: > > > > > > External DMA Mode not supported > > > dwc2_hcd_init() FAILED, returning -22 > > > > Hi Greg, all, > > > > After taking a look at the Octeon driver, it looks like that controller > > uses a customized version of the DWC2 core - it has a different DMA > > engine than the one provided by the standard hardware. So in fact these > > two drivers are actually not "for the same hw". > > FWIW, I also tried forcing the DWC2 to non-DMA/FIFO mode, but could > not get that working either. Do you support any HW running in slave > mode? It seems the RX direction fails. I noticed the dwc2_read_packet() > is hard-coded to channel 0 which looks odd, but changing that didn't > change anything. I have tested FIFO mode on x86 only. It looks like there may be a problem with unaligned RX transfers on archs like ARM that have strict alignment requirements. See this comment in dwc2_read_packet(): * Todo: Account for the case where dest is not dword aligned. Hard-coding to FIFO 0 is correct for RX, since there is only one RX FIFO. -- Paul -- 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
