On Fri, Aug 12, 2011 at 6:46 AM, Sarah Sharp sarah.a.sharp@linux.intel.com wrote:

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?

Yep.

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.

Good :) And I'll make a patch to make double-submission impossible in a nice way.

Daniel