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ALSA: hda: realtek: Fix race at concurrent COEF updates

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The COEF access is done with two steps: setting the index then read or
write the data.  When multiple COEF accesses are performed
concurrently, the index and data might be paired unexpectedly.
In most cases, this isn't a big problem as the COEF setup is done at
the initialization, but some dynamic changes like the mute LED may hit
such a race.

For avoiding the racy COEF accesses, this patch introduces a new
mutex coef_mutex to alc_spec, and wrap the COEF accessing functions
with it.

Reported-by: Alexander Sergeyev <sergeev917@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220111195229.a77wrpjclqwrx4bx@localhost.localdomain
Link: https://lore.kernel.org/r/20220131075738.24323-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2022-01-31 08:57:38 +01:00
parent 0444f82766
commit b837a9f5ab
1 changed files with 50 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
sound/pci/hda/patch_realtek.c
View File

@ -98,6 +98,7 @@ struct alc_spec {
unsigned int gpio_mic_led_mask;
struct alc_coef_led mute_led_coef;
struct alc_coef_led mic_led_coef;
struct mutex coef_mutex;
hda_nid_t headset_mic_pin;
hda_nid_t headphone_mic_pin;
@ -137,8 +138,8 @@ struct alc_spec {
* COEF access helper functions
*/
static int alc_read_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx)
static int __alc_read_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx)
{
unsigned int val;
@ -147,28 +148,61 @@ static int alc_read_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
return val;
}
static int alc_read_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx)
{
struct alc_spec *spec = codec->spec;
unsigned int val;
mutex_lock(&spec->coef_mutex);
val = __alc_read_coefex_idx(codec, nid, coef_idx);
mutex_unlock(&spec->coef_mutex);
return val;
}
#define alc_read_coef_idx(codec, coef_idx) \
alc_read_coefex_idx(codec, 0x20, coef_idx)
static void alc_write_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx, unsigned int coef_val)
static void __alc_write_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx, unsigned int coef_val)
{
snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_COEF_INDEX, coef_idx);
snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_PROC_COEF, coef_val);
}
static void alc_write_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx, unsigned int coef_val)
{
struct alc_spec *spec = codec->spec;
mutex_lock(&spec->coef_mutex);
__alc_write_coefex_idx(codec, nid, coef_idx, coef_val);
mutex_unlock(&spec->coef_mutex);
}
#define alc_write_coef_idx(codec, coef_idx, coef_val) \
alc_write_coefex_idx(codec, 0x20, coef_idx, coef_val)
static void __alc_update_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx, unsigned int mask,
unsigned int bits_set)
{
unsigned int val = __alc_read_coefex_idx(codec, nid, coef_idx);
if (val != -1)
__alc_write_coefex_idx(codec, nid, coef_idx,
(val & ~mask) | bits_set);
}
static void alc_update_coefex_idx(struct hda_codec *codec, hda_nid_t nid,
unsigned int coef_idx, unsigned int mask,
unsigned int bits_set)
{
unsigned int val = alc_read_coefex_idx(codec, nid, coef_idx);
struct alc_spec *spec = codec->spec;
if (val != -1)
alc_write_coefex_idx(codec, nid, coef_idx,
(val & ~mask) | bits_set);
mutex_lock(&spec->coef_mutex);
__alc_update_coefex_idx(codec, nid, coef_idx, mask, bits_set);
mutex_unlock(&spec->coef_mutex);
}
#define alc_update_coef_idx(codec, coef_idx, mask, bits_set) \
@ -201,13 +235,17 @@ struct coef_fw {
static void alc_process_coef_fw(struct hda_codec *codec,
const struct coef_fw *fw)
{
struct alc_spec *spec = codec->spec;
mutex_lock(&spec->coef_mutex);
for (; fw->nid; fw++) {
if (fw->mask == (unsigned short)-1)
alc_write_coefex_idx(codec, fw->nid, fw->idx, fw->val);
__alc_write_coefex_idx(codec, fw->nid, fw->idx, fw->val);
else
alc_update_coefex_idx(codec, fw->nid, fw->idx,
fw->mask, fw->val);
__alc_update_coefex_idx(codec, fw->nid, fw->idx,
fw->mask, fw->val);
}
mutex_unlock(&spec->coef_mutex);
}
/*
@ -1153,6 +1191,7 @@ static int alc_alloc_spec(struct hda_codec *codec, hda_nid_t mixer_nid)
codec->spdif_status_reset = 1;
codec->forced_resume = 1;
codec->patch_ops = alc_patch_ops;
mutex_init(&spec->coef_mutex);
err = alc_codec_rename_from_preset(codec);
if (err < 0) {