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| author | Takashi Iwai <tiwai@suse.de> | 2011-08-19 07:55:10 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2011-08-19 07:55:10 +0200 |
| commit | 38b65190c6ab0be8ce7cff69e734ca5b5e7fa309 (patch) | |
| tree | eeddb399b62b27ef184e87d0bcb8469b3dff5fdd /sound/usb/mixer.c | |
| parent | 3fe45aeaf2033c9eaa5028ed5ba68b466008876f (diff) | |
| download | lwn-38b65190c6ab0be8ce7cff69e734ca5b5e7fa309.tar.gz lwn-38b65190c6ab0be8ce7cff69e734ca5b5e7fa309.zip | |
ALSA: usb-audio - Fix missing mixer dB information
The recent fix for testing dB range at the mixer creation time seems
to cause regressions in some devices. In such devices, reading the dB
info at probing time gives an error, thus both dBmin and dBmax are still
zero, and TLV flag isn't set although the later read of dB info succeeds.
This patch adds a workaround for such a case by assuming that the later
read will succeed. In future, a similar test should be performed in a
case where a wrong dB range is seen even in the later read.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>
Diffstat (limited to 'sound/usb/mixer.c')
| -rw-r--r-- | sound/usb/mixer.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index c04d7c71ac88..cdd19d7fe500 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -152,6 +152,7 @@ static inline void check_mapped_dB(const struct usbmix_name_map *p, if (p && p->dB) { cval->dBmin = p->dB->min; cval->dBmax = p->dB->max; + cval->initialized = 1; } } @@ -1092,7 +1093,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, " Switch" : " Volume"); if (control == UAC_FU_VOLUME) { check_mapped_dB(map, cval); - if (cval->dBmin < cval->dBmax) { + if (cval->dBmin < cval->dBmax || !cval->initialized) { kctl->tlv.c = mixer_vol_tlv; kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ | |