On Mon, 29 Oct 2012, Simon Farnsworth wrote: > On Monday 29 October 2012 13:44:45 Mauro Carvalho Chehab wrote: > > Thanks for digging into it and getting more data. Do you know if this change > > it also needed with USB devices that do DMA (isoc and/or bulk)? Or the USB > > core already handles that? > > > I'm not a huge expert - the linux-pm list (cc'd) will have people around who > know more. > > If I've understood correctly, though, the USB core should take care of pm_qos > requests if they're needed for the hardware; remember that if the HCD has > enough buffering, there's no need for a pm_qos request.
The USB core is not PM-QOS aware. It relies on the PM core to tell it when devices may safely be runtime-suspended. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
