On Sat, 21 Apr 2018 06:20:46 +0200, Jeffery Miller wrote:
The commit c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code") changed SNDRV_PCM_IOCTL_DELAY to return an inconsistent error instead of a negative delay. Originally the call would succeed and return the negative delay. The Chromium OS Audio Server (CRAS) gets confused and hangs when the error is returned instead of the negative delay.
Help CRAS avoid the issue by rolling back the behavior to return a negative delay instead of an error.
Fixes: c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code") Signed-off-by: Jeffery Miller jmiller@neverware.com
This patch changes the SNDRV_PCM_IOCTL_DELAY ioctl return behavior to be similar to what it was in an earlier kernel. I encountered this when upgrading from the 4.4 kernel to 4.14. Chrome Audio Server (cras) does not handle the error return as gracefully as it was handling the successful but negative delays.
The intent of this patch is to simply revert the behavior of the call to match what it was previously.
It has been applied and tested with the 4.14 kernel. I did confirm this is still an issue and is resolved with the patch on the tiwai/sound.git master branch.
This is an oversight, indeed. Applied now.
thanks,
Takashi