On Fri, 22 Oct 2010, Bensaid, Selma wrote: > Hi, > > I have question concerning ALSA Core snd_pcm_control_ioctl function. > > I have noticed that the IOCTL fails if it's called for a device with > substream_count = 0, since I'm implementing a PCM device that supports > Record and does not support Playback, the IOCTL fails when called for > the Playback stream. I would propose, in such case, to return that the > stream has 0 playback substreams instead of failing. You mean probably that the SNDRV_CTL_IOCTL_PCM_INFO ioctl returns -ENOENT when an invalid direction is accessed. It looks correct to me. If a direction does not exist, it makes no sense to gather info for it. And -ENOENT response clearly shows that this direction is not available, so the user space tools can distict if it's an unexpected error or this one. Jaroslav ----- Jaroslav Kysela <perex@xxxxxxxx> Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
