The fix for a long-standing USB-audio bug required one more dependency variable to be added to the hw constraints. Unfortunately I didn't realize at debugging that the new addition may result in the overflow of the dependency array of each snd_pcm_hw_rule (up to three plus a sentinel), because USB-audio driver adds one more dependency only for a certain device and bus, hence it works as is for many devices. But in a bad case, a simple open always results in -EINVAL (with kernel WARNING if CONFIG_SND_DEBUG is set) no matter what is passed.

Since the dependencies are real and unavoidable (USB-audio restricts the hw_params per looping over the format/rate/channels combos), the only good solution seems to raise the bar for one more dependency for snd_pcm_hw_rule -- so does this patch: now the hw constraint dependencies can be up to four.

Fixes: 506c203cc3de ("ALSA: usb-audio: Fix hw constraints dependencies") Reported-by: Jamie Heilman jamie@audible.transient.net Signed-off-by: Takashi Iwai tiwai@suse.de --- include/sound/pcm.h | 2 +- sound/core/pcm_native.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 2336bf9243e1..2e1200d17d0c 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -229,7 +229,7 @@ typedef int (*snd_pcm_hw_rule_func_t)(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule { unsigned int cond; int var; - int deps[4]; + int deps[5];

snd_pcm_hw_rule_func_t func; void *private; diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 9f3f8e953ff0..c4aac703dc22 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -382,8 +382,8 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream, continue;

/* - * The 'deps' array includes maximum three dependencies - * to SNDRV_PCM_HW_PARAM_XXXs for this rule. The fourth + * The 'deps' array includes maximum four dependencies + * to SNDRV_PCM_HW_PARAM_XXXs for this rule. The fifth * member of this array is a sentinel and should be * negative value. *