[alsa-devel] [PATCH sound-unstable] usb-audio: sync ep init fix for audioformat mismatch

Eldad Zack eldad at fogrefinery.com
Thu Dec 6 22:34:56 CET 2012

On Tue, 4 Dec 2012, Takashi Iwai wrote:
> At Mon,  3 Dec 2012 20:30:09 +0100,
> Eldad Zack wrote:
> > 
> > Commit 947d299686aa9cc8aecf749d54e8475c6e498956 , "ALSA: snd-usb:
> > properly initialize the sync endpoint", while correcting the
> > initialization of the sync endpoint when opening just the data
> > endpoint, prevents devices that has a sync endpoint, with a channel
> > number different than that of the data endpoint, from functioning.
> > Due to a different channel and period bytes count, attempting to
> > initialize the sync endpoint will fail at the usb host driver.
> > For example, when using xhci:
> > 
> >  cannot submit urb 0, error -90: internal error
> > 
> > With this patch, if a sync endpoint has multiple audioformats, a
> > matching audioformat is preferred. An audioformat must be found
> > with at least one channel and support the requested sample rate
> > and PCM format, otherwise the stream will not be opened.
> > 
> > If the number of channels differ between the selected audioformat
> > and the requested format, adjust the period bytes count accordingly.
> > It is safe to perform the calculation on the basis of the channel
> > count, since the requested PCM audio format and the rate must be
> > supported by the selected audioformat.
> > 
> > Cc: Jeffrey Barish <jeff_barish at earthlink.net>
> > Cc: Daniel Mack <zonque at gmail.com>
> > Signed-off-by: Eldad Zack <eldad at fogrefinery.com>
> Thanks, applied.


> At the next time, however, create a patch based on either for-next or
> for-linus branch of sound git tree.  sound-unstable tree is a place to
> play with experimental patches.  The place to put the real patches
> that will be fed to the upstream is sound git tree.

Ah, sorry, I mixed up unstable with to-next then.
Thanks for the heads up! 


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