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authorTakashi Iwai <tiwai@suse.de>2011-08-19 07:55:10 +0200
committerTakashi Iwai <tiwai@suse.de>2011-08-19 07:55:10 +0200
commit38b65190c6ab0be8ce7cff69e734ca5b5e7fa309 (patch)
treeeeddb399b62b27ef184e87d0bcb8469b3dff5fdd
parent3fe45aeaf2033c9eaa5028ed5ba68b466008876f (diff)
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>
-rw-r--r--sound/usb/mixer.c3
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 |