Hi Michael, On 03.04.2013 16:11, Michael Trimarchi wrote: > On 03/04/13 15:55, Michael Trimarchi wrote: >> On 03/04/13 12:23, Daniel Mack wrote: >>> Hi David, >>> >>> On 03.04.2013 12:15, David Henningsson wrote: >>>> Just to get your attention here on what seems to be an USB audio >>>> regression. >>>> >>>> The bug is described in detail here: >>>> >>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110?comments=all >>>> >>>> Quoting the bug: >>>> >>>> " >>>> This bug seems to affect only a certain kind of hardware, which is >>>> called "Asynchronous USB Digital Audio Codec (DAC)". It's said that such >>>> a DAC hosts the clock itself (USB Device Host). An ordinary DAC, so >>>> called "Synchronous USB DAC", uses the clock hosted by the mother board, >>>> which is not affected by this bug. >>>> >>>> When this bug affects an asynchronous USB DAC, the audio played by the >>>> DAC is constantly interrupted. The playback itself does not stop, but >>>> the output becomes discontinous, filling with constant crackling noises, >>>> destroying everything the DAC plays. >>>> " >>>> >>>> According to the bug reporter, which seems to have done quite a bit of >>>> research, this started between 3.8-rc6 and 3.8-rc7 as well as stable >>>> kernels and the bug also lists a few commits which could be the cause, >>>> none under sound/usb though. >>> >>> There were no relevant changes for snd-usb between the two versions >>> mentioned. The only patches that come in mind in this time window are: >>> >>> 3e619d041 "USB: EHCI: fix bug in scheduling periodic split transfers" >>> b09a61cc0 "USB: EHCI: fix for leaking isochronous data" >> >> This last one, doesn't give me any problem, just a memory leak and not a choppy >> playback (tested on 48Khz, 96Khz, 192Khz 32bit on OMAP3 device) and I don't >> think that it can be the reason of the problem. Is OMAP3 at all a platform that is affected by the bug? It seems the effect is only seen on some special host controller hardware anyway. > Sorry the comment was for a bug that is not included in this list and recently fixed. > USB: EHCI: fix bug in iTD/siTD DMA pool allocation Sorry, you lost me. So what's the status of this issue now? Does "USB: EHCI: fix bug in iTD/siTD DMA pool allocation" fix it? If not - and assuming you can reproduce the bug - which patches of the two I mentioned did you revert, and what was the effect of that? Did you try and remove both as well? Thanks, Daniel _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
