Messages in this thread | | | Date | Thu, 11 Aug 2011 21:46:05 -0700 | From | Sarah Sharp <> | Subject | Re: Allocating buffers for USB transfers (again) |
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On Fri, Aug 12, 2011 at 03:28:42AM +0200, Daniel Mack wrote: > On Fri, Aug 12, 2011 at 1:50 AM, Matěj Laitl <matej@laitl.cz> wrote: > > On 12. 8. 2011 Daniel Mack wrote: > >> > This patch actually makes the sound playback _worse_. Now I get strange > >> > squawks where previously at least first seconds of a song sounded > >> > normally. > >> > > >> > However, I no longer get "zero length buffer submitted" or that "... > >> > Weird." debug messages, only several megabytes of: (should I post these > >> > somewhere?) > >> > > >> > xhci_hcd 0000:05:00.0: Giveback URB ffff880114cec000, len = 880, > >> > expected = 1000, status = -115 > >> > xhci_hcd 0000:05:00.0: Giveback URB ffff880114740000, len = 352, > >> > expected = 1000, status = -115 > >> > xhci_hcd 0000:05:00.0: underrun event on endpoint > >> > >> Might be the hardware doesn't like this. As I said, the patch is blindly > >> written and I couldn't test it. Did you test this on a EHCI port as well? > > > > Good point, this patch distorts the playback also on the EHCI port. (the > > playback seems to be 10 times slower than it should be) > > And it is only this *last* patch that causes it, yes? > > If that is the case, we need empty subframes in the middle of urbs, > and we need to figure a way how to teach the XHCI driver to cope with > that, too.
By empty subframes, you mean zero-length frame buffers in the middle of the URB, correct? Andiry and Alan had some suggestions for how to fix that, so I'll try to cook up a patch tomorrow. Then we'll have to "unpeel" the debug patches and make sure the system is still usable.
Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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