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authorTakashi Iwai <tiwai@suse.de>2021-01-23 16:57:30 +0100
committerTakashi Iwai <tiwai@suse.de>2021-01-23 16:59:24 +0100
commit23b53d4417426edc7c3078e1c1530c242e496c1e (patch)
tree63999a0395d92e7c3f2b7c54aab0070c6d49135a /sound/core
parent5de3b9430221b11a5e1fc2f5687af80777c8392a (diff)
downloadlinux-23b53d4417426edc7c3078e1c1530c242e496c1e.tar.gz
ALSA: pcm: One more dependency for hw constraints
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>
Link: https://lore.kernel.org/r/20210123155730.22576-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/pcm_native.c4
1 files changed, 2 insertions, 2 deletions
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 @@ retry:
 			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.
 		 *