From: Takashi Iwai <tiwai@suse.de>
To: linux-sound@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 7/8] ALSA: usb-audio: Fix mixer bitmap cache over 32 channels
Date: Tue, 6 Oct 2026 15:40:31 +0200 [thread overview]
Message-ID: <20261006134035.478529-8-tiwai@suse.de> (raw)
In-Reply-To: <20261006134035.478529-1-tiwai@suse.de>
USB-audio driver keeps the bitmap for the cached mixer channels, but
since a 32bit integer is used, it's currently broken for over 32
channels. As the driver is supposed to support up to 64 channels,
this patch extends the bitmap properly -- now to be more flexible, use
the standard bitmap instead of the manual bit shifts.
Some checks for master channels are replaced in a slightly different
manner (checking the channel index 0) instead of the full cval->cached
check, so that it fits better in the bitmap helper usage.
Fixes: 16ee07bfa935 ("ALSA: usb-audio: Extend max number of channels to 64")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/mixer.c | 18 +++++++++---------
sound/usb/mixer.h | 2 +-
sound/usb/mixer_scarlett.c | 18 +++++++++---------
sound/usb/mixer_us16x08.c | 20 ++++++++++----------
4 files changed, 29 insertions(+), 29 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index bc71d7210eb2..8bd57a581fc1 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -423,7 +423,7 @@ int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
{
int err;
- if (cval->cached & BIT(channel)) {
+ if (test_bit(channel, cval->cached)) {
*value = cval->cache_val[index];
return 0;
}
@@ -440,7 +440,7 @@ int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
cval->control, channel, err);
return err;
}
- cval->cached |= BIT(channel);
+ set_bit(channel, cval->cached);
cval->cache_val[index] = *value;
return 0;
}
@@ -604,7 +604,7 @@ int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
value);
if (err < 0)
return err;
- cval->cached |= BIT(channel);
+ set_bit(channel, cval->cached);
cval->cache_val[index] = value;
return 0;
}
@@ -1449,7 +1449,7 @@ static int get_min_max_with_quirks(struct usb_mixer_elem_info *cval,
* properly.
*/
if (ret)
- cval->cached = 0;
+ bitmap_zero(cval->cached, MAX_CHANNELS + 1);
cval->initialized = 1;
}
@@ -3667,7 +3667,7 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
info = mixer_elem_list_to_info(list);
/* invalidate cache, so the value is read from the device */
if (!info->get_cur_broken)
- info->cached = 0;
+ bitmap_zero(info->cached, MAX_CHANNELS + 1);
snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
&list->kctl->id);
}
@@ -3766,9 +3766,9 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
/* invalidate cache, so the value is read from the device */
if (!info->get_cur_broken) {
if (channel)
- info->cached &= ~BIT(channel);
+ clear_bit(channel, info->cached);
else /* master channel */
- info->cached = 0;
+ bitmap_zero(info->cached, MAX_CHANNELS + 1);
}
snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
@@ -4005,7 +4005,7 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list)
for (c = 0; c < MAX_CHANNELS; c++) {
if (!(cval->cmask & BIT(c)))
continue;
- if (cval->cached & BIT(c + 1)) {
+ if (test_bit(c + 1, cval->cached)) {
err = snd_usb_set_cur_mix_value(cval, c + 1, idx,
cval->cache_val[idx]);
if (err < 0)
@@ -4015,7 +4015,7 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list)
}
} else {
/* master */
- if (cval->cached)
+ if (test_bit(0, cval->cached))
snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val);
}
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 2ff4490f97c2..0d0a8b343756 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -93,7 +93,7 @@ struct usb_mixer_elem_info {
int min, max, res;
int max_exposed; /* control API exposes the value in 0..max_exposed */
int dBmin, dBmax;
- int cached;
+ DECLARE_BITMAP(cached, MAX_CHANNELS + 1);
int cache_val[MAX_CHANNELS];
u8 initialized;
u8 min_mute;
diff --git a/sound/usb/mixer_scarlett.c b/sound/usb/mixer_scarlett.c
index 369968565c19..6808730ef047 100644
--- a/sound/usb/mixer_scarlett.c
+++ b/sound/usb/mixer_scarlett.c
@@ -292,7 +292,7 @@ static int forte_get_ctl_value(struct usb_mixer_elem_info *elem, int *value)
/* Device may not support reading input controls.
* Return cached value or default to avoid blocking module load.
*/
- if (elem->cached)
+ if (test_bit(0, elem->cached))
*value = elem->cache_val[0];
else
*value = 0; /* Default: first option */
@@ -353,7 +353,7 @@ static int forte_input_gain_put(struct snd_kcontrol *kctl,
err = forte_set_ctl_value(elem, val);
if (err < 0)
return err;
- elem->cached |= 1;
+ set_bit(0, elem->cached);
elem->cache_val[0] = val;
return 1;
}
@@ -364,7 +364,7 @@ static int forte_input_gain_resume(struct usb_mixer_elem_list *list)
{
struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
- if (elem->cached)
+ if (test_bit(0, elem->cached))
forte_set_ctl_value(elem, *elem->cache_val);
return 0;
}
@@ -405,7 +405,7 @@ static int forte_ctl_enum_put(struct snd_kcontrol *kctl,
err = forte_set_ctl_value(elem, val);
if (err < 0)
return err;
- elem->cached |= 1;
+ set_bit(0, elem->cached);
elem->cache_val[0] = val;
return 1;
}
@@ -416,7 +416,7 @@ static int forte_ctl_enum_resume(struct usb_mixer_elem_list *list)
{
struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
- if (elem->cached)
+ if (test_bit(0, elem->cached))
forte_set_ctl_value(elem, *elem->cache_val);
return 0;
}
@@ -454,7 +454,7 @@ static int forte_ctl_switch_put(struct snd_kcontrol *kctl,
err = forte_set_ctl_value(elem, val);
if (err < 0)
return err;
- elem->cached |= 1;
+ set_bit(0, elem->cached);
elem->cache_val[0] = val;
return 1;
}
@@ -465,7 +465,7 @@ static int forte_ctl_switch_resume(struct usb_mixer_elem_list *list)
{
struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
- if (elem->cached)
+ if (test_bit(0, elem->cached))
forte_set_ctl_value(elem, *elem->cache_val);
return 0;
}
@@ -532,7 +532,7 @@ static int scarlett_ctl_resume(struct usb_mixer_elem_list *list)
int i;
for (i = 0; i < elem->channels; i++)
- if (elem->cached & (1 << i))
+ if (test_bit(i, elem->cached))
snd_usb_set_cur_mix_value(elem, i, i,
elem->cache_val[i]);
return 0;
@@ -692,7 +692,7 @@ static int scarlett_ctl_enum_resume(struct usb_mixer_elem_list *list)
{
struct usb_mixer_elem_info *elem = mixer_elem_list_to_info(list);
- if (elem->cached)
+ if (test_bit(0, elem->cached))
snd_usb_set_cur_mix_value(elem, 0, 0, *elem->cache_val);
return 0;
}
diff --git a/sound/usb/mixer_us16x08.c b/sound/usb/mixer_us16x08.c
index 14fb1ad764a7..8e5ccd3282a7 100644
--- a/sound/usb/mixer_us16x08.c
+++ b/sound/usb/mixer_us16x08.c
@@ -236,7 +236,7 @@ static int snd_us16x08_route_put(struct snd_kcontrol *kcontrol,
return err;
}
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -295,7 +295,7 @@ static int snd_us16x08_master_put(struct snd_kcontrol *kcontrol,
return err;
}
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -336,7 +336,7 @@ static int snd_us16x08_bus_put(struct snd_kcontrol *kcontrol,
return err;
}
- elem->cached |= 1;
+ set_bit(0, elem->cached);
elem->cache_val[0] = val;
return 1;
}
@@ -404,7 +404,7 @@ static int snd_us16x08_channel_put(struct snd_kcontrol *kcontrol,
return err;
}
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -508,7 +508,7 @@ static int snd_us16x08_comp_put(struct snd_kcontrol *kcontrol,
}
store->val[val_idx][index] = val;
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -567,7 +567,7 @@ static int snd_us16x08_eqswitch_put(struct snd_kcontrol *kcontrol,
return err;
}
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -631,7 +631,7 @@ static int snd_us16x08_eq_put(struct snd_kcontrol *kcontrol,
store->val[b_idx][p_idx][index] = val;
/* store new value in EQ band cache */
- elem->cached |= 1 << index;
+ set_bit(index, elem->cached);
elem->cache_val[index] = val;
return 1;
}
@@ -1352,7 +1352,7 @@ int snd_us16x08_controls_create(struct usb_mixer_interface *mixer)
}
for (i = 0; i < 8; i++)
elem->cache_val[i] = i < 2 ? i : i + 2;
- elem->cached = 0xff;
+ bitmap_set(elem->cached, 0, 8);
/* create compressor mixer elements */
comp_store = snd_us16x08_create_comp_store();
@@ -1374,7 +1374,7 @@ int snd_us16x08_controls_create(struct usb_mixer_interface *mixer)
if (err < 0)
return err;
elem->cache_val[0] = master_controls[i].default_val;
- elem->cached = 1;
+ set_bit(0, elem->cached);
}
/* add channel controls */
@@ -1394,7 +1394,7 @@ int snd_us16x08_controls_create(struct usb_mixer_interface *mixer)
elem->cache_val[j] =
channel_controls[i].default_val;
}
- elem->cached = 0xffff;
+ bitmap_set(elem->cached, 0, SND_US16X08_MAX_CHANNELS);
}
/* create eq store */
--
2.55.0
next prev parent reply other threads:[~2026-10-06 13:40 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-06 13:40 [PATCH 0/8] ALSA: Fix some bugs reported by Sashiko Takashi Iwai
2026-10-06 13:40 ` [PATCH 1/8] ALSA: seq: Drop the bogus RCU guard from clientptr() Takashi Iwai
2026-10-06 13:40 ` [PATCH 2/8] ALSA: pcm: Fix TOCTOU state overwrite in snd_pcm_drop() Takashi Iwai
2026-10-06 13:40 ` [PATCH 3/8] ALSA: hda: Fix potential UAF for gating jack Takashi Iwai
2026-10-06 13:40 ` [PATCH 4/8] ALSA: usb-audio: Fix invalid UAC2/3 mixer unit matrix evaluation Takashi Iwai
2026-10-06 13:40 ` [PATCH 5/8] ALSA: usb-audio: Fix data race at mixer_ctl_feature_info() Takashi Iwai
2026-10-06 13:40 ` [PATCH 6/8] ALSA: pcmtest: Fix a bogus pointer read in snd_pcmtst_pcm_pointer() Takashi Iwai
2026-10-06 13:40 ` Takashi Iwai [this message]
2026-10-06 13:40 ` [PATCH 8/8] ALSA: core: Add missing barriers for power_ref vs card->shutdown Takashi Iwai
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