@@ -981,6 +981,7 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
hw_rule_rate, subs,
+ SNDRV_PCM_HW_PARAM_RATE,
SNDRV_PCM_HW_PARAM_FORMAT,
SNDRV_PCM_HW_PARAM_CHANNELS,
param_period_time_if_needed,
@@ -990,6 +991,7 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
hw_rule_channels, subs,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
SNDRV_PCM_HW_PARAM_FORMAT,
SNDRV_PCM_HW_PARAM_RATE,
param_period_time_if_needed,
@@ -998,6 +1000,7 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
return err;
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
hw_rule_format, subs,
+ SNDRV_PCM_HW_PARAM_FORMAT,
SNDRV_PCM_HW_PARAM_RATE,
SNDRV_PCM_HW_PARAM_CHANNELS,
param_period_time_if_needed,
Since the recent refactoring, it's been reported that some USB-audio devices (typically webcams) are no longer detected properly by PulseAudio. The debug session revealed that it's failing at probing by PA to try the sample rate 44.1kHz while the device has discrete sample rates other than 44.1kHz. But the puzzle was that arecord works as is, and some other devices with the discrete rates work, either. After all, this turned out to be the lack of the dependencies in a few hw constraint rules: snd_pcm_hw_rule_add() has the (variable) arguments specifying the dependent parameters, and some functions didn't set the target parameter itself as the dependencies. This resulted in an invalid parameter that could be generated only in a certain call pattern. This bug itself has been present in the code, but it didn't trigger errors just because the rules were casually avoiding such a corner case. After the recent refactoring and cleanup, however, the hw constraints work "as expected", and the problem surfaced now. For fixing the problem above, this patch adds the missing dependent parameters to each snd_pcm_hw_rule() call. Fixes: bc4e94aa8e72 ("ALSA: usb-audio: Handle discrete rates properly in hw constraints") BugLink: http://bugzilla.opensuse.org/show_bug.cgi?id=1181014 Signed-off-by: Takashi Iwai <tiwai@suse.de> --- sound/usb/pcm.c | 3 +++ 1 file changed, 3 insertions(+)