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ALSA: hda: Manage concurrent reg access more properly 

In the commit 8e85def572 ("ALSA: hda: enable regmap internal
locking"), we re-enabled the regmap lock due to the reported
regression that showed the possible concurrent accesses.  It was a
temporary workaround, and there are still a few opened races even
after the revert.  In this patch, we cover those still opened windows
with a proper mutex lock and disable the regmap internal lock again.

First off, the patch introduces a new snd_hdac_device.regmap_lock
mutex that is applied for each snd_hdac_regmap_*() call, including
read, write and update helpers.  The mutex is applied carefully so
that it won't block the self-power-up procedure in the helper
function.  Also, this assures the protection for the accesses without
regmap, too.

The snd_hdac_regmap_update_raw() is refactored to use the standard
regmap_update_bits_check() function instead of the open-code.  The
non-regmap case is still open-coded but it's an easy part.  The all
read and write operations are in the single mutex protection, so it's
now race-free.

In addition, a couple of new helper functions are added:
snd_hdac_regmap_update_raw_once() and snd_hdac_regmap_sync().  Both
are called from HD-audio legacy driver.  The former is to initialize
the given verb bits but only once when it's not initialized yet.  Due
to this condition, the function invokes regcache_cache_only(), and
it's now performed inside the regmap_lock (formerly it was racy) too.
The latter function is for simply invoking regcache_sync() inside the
regmap_lock, which is called from the codec resume call path.
Along with that, the HD-audio codec driver code is slightly modified /
simplified to adapt those new functions.

And finally, snd_hdac_regmap_read_raw(), *_write_raw(), etc are
rewritten with the helper macro.  It's just for simplification because
the code logic is identical among all those functions.

Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200109090104.26073-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2020-01-09 10:01:04 +01:00
parent 73ac9f5e5b
commit 1a462be52f
10 changed files with 135 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/sound/hda_regmap.h
View File

@ -24,6 +24,9 @@ int snd_hdac_regmap_write_raw(struct hdac_device *codec, unsigned int reg,
unsigned int val);
int snd_hdac_regmap_update_raw(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val);
int snd_hdac_regmap_update_raw_once(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val);
void snd_hdac_regmap_sync(struct hdac_device *codec);
/**
* snd_hdac_regmap_encode_verb - encode the verb to a pseudo register

1
include/sound/hdaudio.h
View File

@ -86,6 +86,7 @@ struct hdac_device {
/* regmap */
struct regmap *regmap;
struct mutex regmap_lock;
struct snd_array vendor_verbs;
bool lazy_cache:1; /* don't wake up for writes */
bool caps_overwriting:1; /* caps overwrite being in process */

1
sound/hda/hdac_device.c
View File

@ -57,6 +57,7 @@ int snd_hdac_device_init(struct hdac_device *codec, struct hdac_bus *bus,
codec->addr = addr;
codec->type = HDA_DEV_CORE;
mutex_init(&codec->widget_lock);
mutex_init(&codec->regmap_lock);
pm_runtime_set_active(&codec->dev);
pm_runtime_get_noresume(&codec->dev);
atomic_set(&codec->in_pm, 0);

142
sound/hda/hdac_regmap.c
View File

@ -363,6 +363,7 @@ static const struct regmap_config hda_regmap_cfg = {
.reg_write = hda_reg_write,
.use_single_read = true,
.use_single_write = true,
.disable_locking = true,
};
/**
@ -425,12 +426,29 @@ EXPORT_SYMBOL_GPL(snd_hdac_regmap_add_vendor_verb);
static int reg_raw_write(struct hdac_device *codec, unsigned int reg,
unsigned int val)
{
int err;
mutex_lock(&codec->regmap_lock);
if (!codec->regmap)
return hda_reg_write(codec, reg, val);
err = hda_reg_write(codec, reg, val);
else
return regmap_write(codec->regmap, reg, val);
err = regmap_write(codec->regmap, reg, val);
mutex_unlock(&codec->regmap_lock);
return err;
}
/* a helper macro to call @func_call; retry with power-up if failed */
#define CALL_RAW_FUNC(codec, func_call) \
({ \
int _err = func_call; \
if (_err == -EAGAIN) { \
_err = snd_hdac_power_up_pm(codec); \
if (_err >= 0) \
_err = func_call; \
snd_hdac_power_down_pm(codec); \
} \
_err;})
/**
* snd_hdac_regmap_write_raw - write a pseudo register with power mgmt
* @codec: the codec object
@ -442,42 +460,29 @@ static int reg_raw_write(struct hdac_device *codec, unsigned int reg,
int snd_hdac_regmap_write_raw(struct hdac_device *codec, unsigned int reg,
unsigned int val)
{
int err;
err = reg_raw_write(codec, reg, val);
if (err == -EAGAIN) {
err = snd_hdac_power_up_pm(codec);
if (err >= 0)
err = reg_raw_write(codec, reg, val);
snd_hdac_power_down_pm(codec);
}
return err;
return CALL_RAW_FUNC(codec, reg_raw_write(codec, reg, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_write_raw);
static int reg_raw_read(struct hdac_device *codec, unsigned int reg,
unsigned int *val, bool uncached)
{
int err;
mutex_lock(&codec->regmap_lock);
if (uncached || !codec->regmap)
return hda_reg_read(codec, reg, val);
err = hda_reg_read(codec, reg, val);
else
return regmap_read(codec->regmap, reg, val);
err = regmap_read(codec->regmap, reg, val);
mutex_unlock(&codec->regmap_lock);
return err;
}
static int __snd_hdac_regmap_read_raw(struct hdac_device *codec,
unsigned int reg, unsigned int *val,
bool uncached)
{
int err;
err = reg_raw_read(codec, reg, val, uncached);
if (err == -EAGAIN) {
err = snd_hdac_power_up_pm(codec);
if (err >= 0)
err = reg_raw_read(codec, reg, val, uncached);
snd_hdac_power_down_pm(codec);
}
return err;
return CALL_RAW_FUNC(codec, reg_raw_read(codec, reg, val, uncached));
}
/**
@ -504,6 +509,35 @@ int snd_hdac_regmap_read_raw_uncached(struct hdac_device *codec,
return __snd_hdac_regmap_read_raw(codec, reg, val, true);
}
static int reg_raw_update(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val)
{
unsigned int orig;
bool change;
int err;
mutex_lock(&codec->regmap_lock);
if (codec->regmap) {
err = regmap_update_bits_check(codec->regmap, reg, mask, val,
&change);
if (!err)
err = change ? 1 : 0;
} else {
err = hda_reg_read(codec, reg, &orig);
if (!err) {
val &= mask;
val |= orig & ~mask;
if (val != orig) {
err = hda_reg_write(codec, reg, val);
if (!err)
err = 1;
}
}
}
mutex_unlock(&codec->regmap_lock);
return err;
}
/**
* snd_hdac_regmap_update_raw - update a pseudo register with power mgmt
* @codec: the codec object
@ -515,20 +549,58 @@ int snd_hdac_regmap_read_raw_uncached(struct hdac_device *codec,
*/
int snd_hdac_regmap_update_raw(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val)
{
return CALL_RAW_FUNC(codec, reg_raw_update(codec, reg, mask, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_update_raw);
static int reg_raw_update_once(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val)
{
unsigned int orig;
int err;
val &= mask;
err = snd_hdac_regmap_read_raw(codec, reg, &orig);
if (!codec->regmap)
return reg_raw_update(codec, reg, mask, val);
mutex_lock(&codec->regmap_lock);
regcache_cache_only(codec->regmap, true);
err = regmap_read(codec->regmap, reg, &orig);
regcache_cache_only(codec->regmap, false);
if (err < 0)
return err;
val |= orig & ~mask;
if (val == orig)
return 0;
err = snd_hdac_regmap_write_raw(codec, reg, val);
if (err < 0)
return err;
return 1;
err = regmap_update_bits(codec->regmap, reg, mask, val);
mutex_unlock(&codec->regmap_lock);
return err;
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_update_raw);
/**
* snd_hdac_regmap_update_raw_once - initialize the register value only once
* @codec: the codec object
* @reg: pseudo register
* @mask: bit mask to update
* @val: value to update
*
* Performs the update of the register bits only once when the register
* hasn't been initialized yet. Used in HD-audio legacy driver.
* Returns zero if successful or a negative error code
*/
int snd_hdac_regmap_update_raw_once(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val)
{
return CALL_RAW_FUNC(codec, reg_raw_update_once(codec, reg, mask, val));
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_update_raw_once);
/**
* snd_hdac_regmap_sync - sync out the cached values for PM resume
* @codec: the codec object
*/
void snd_hdac_regmap_sync(struct hdac_device *codec)
{
if (codec->regmap) {
mutex_lock(&codec->regmap_lock);
regcache_sync(codec->regmap);
mutex_unlock(&codec->regmap_lock);
}
}
EXPORT_SYMBOL_GPL(snd_hdac_regmap_sync);

30
sound/pci/hda/hda_codec.c
View File

@ -1267,6 +1267,18 @@ int snd_hda_override_amp_caps(struct hda_codec *codec, hda_nid_t nid, int dir,
}
EXPORT_SYMBOL_GPL(snd_hda_override_amp_caps);
static unsigned int encode_amp(struct hda_codec *codec, hda_nid_t nid,
int ch, int dir, int idx)
{
unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
/* enable fake mute if no h/w mute but min=mute */
if ((query_amp_caps(codec, nid, dir) &
(AC_AMPCAP_MUTE | AC_AMPCAP_MIN_MUTE)) == AC_AMPCAP_MIN_MUTE)
cmd |= AC_AMP_FAKE_MUTE;
return cmd;
}
/**
* snd_hda_codec_amp_update - update the AMP mono value
* @codec: HD-audio codec
@ -1282,12 +1294,8 @@ EXPORT_SYMBOL_GPL(snd_hda_override_amp_caps);
int snd_hda_codec_amp_update(struct hda_codec *codec, hda_nid_t nid,
int ch, int dir, int idx, int mask, int val)
{
unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
unsigned int cmd = encode_amp(codec, nid, ch, dir, idx);
/* enable fake mute if no h/w mute but min=mute */
if ((query_amp_caps(codec, nid, dir) &
(AC_AMPCAP_MUTE | AC_AMPCAP_MIN_MUTE)) == AC_AMPCAP_MIN_MUTE)
cmd |= AC_AMP_FAKE_MUTE;
return snd_hdac_regmap_update_raw(&codec->core, cmd, mask, val);
}
EXPORT_SYMBOL_GPL(snd_hda_codec_amp_update);
@ -1335,16 +1343,11 @@ EXPORT_SYMBOL_GPL(snd_hda_codec_amp_stereo);
int snd_hda_codec_amp_init(struct hda_codec *codec, hda_nid_t nid, int ch,
int dir, int idx, int mask, int val)
{
int orig;
unsigned int cmd = encode_amp(codec, nid, ch, dir, idx);
if (!codec->core.regmap)
return -EINVAL;
regcache_cache_only(codec->core.regmap, true);
orig = snd_hda_codec_amp_read(codec, nid, ch, dir, idx);
regcache_cache_only(codec->core.regmap, false);
if (orig >= 0)
return 0;
return snd_hda_codec_amp_update(codec, nid, ch, dir, idx, mask, val);
return snd_hdac_regmap_update_raw_once(&codec->core, cmd, mask, val);
}
EXPORT_SYMBOL_GPL(snd_hda_codec_amp_init);
@ -2905,8 +2908,7 @@ static void hda_call_codec_resume(struct hda_codec *codec)
else {
if (codec->patch_ops.init)
codec->patch_ops.init(codec);
if (codec->core.regmap)
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
}
if (codec->jackpoll_interval)

2
sound/pci/hda/hda_generic.c
View File

@ -6027,7 +6027,7 @@ int snd_hda_gen_init(struct hda_codec *codec)
/* call init functions of standard auto-mute helpers */
update_automute_all(codec);
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
if (spec->vmaster_mute.sw_kctl && spec->vmaster_mute.hook)
snd_hda_sync_vmaster_hook(&spec->vmaster_mute);

2
sound/pci/hda/hda_local.h
View File

@ -138,6 +138,8 @@ int snd_hda_codec_reset(struct hda_codec *codec);
void snd_hda_codec_register(struct hda_codec *codec);
void snd_hda_codec_cleanup_for_unbind(struct hda_codec *codec);
#define snd_hda_regmap_sync(codec) snd_hdac_regmap_sync(&(codec)->core)
enum {
HDA_VMUTE_OFF,
HDA_VMUTE_ON,

2
sound/pci/hda/patch_hdmi.c
View File

@ -2404,7 +2404,7 @@ static int generic_hdmi_resume(struct hda_codec *codec)
int pin_idx;
codec->patch_ops.init(codec);
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);

4
sound/pci/hda/patch_realtek.c
View File

@ -907,7 +907,7 @@ static int alc_resume(struct hda_codec *codec)
if (!spec->no_depop_delay)
msleep(150); /* to avoid pop noise */
codec->patch_ops.init(codec);
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
hda_call_check_power_status(codec, 0x01);
return 0;
}
@ -3638,7 +3638,7 @@ static int alc269_resume(struct hda_codec *codec)
msleep(200);
}
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
hda_call_check_power_status(codec, 0x01);
/* on some machine, the BIOS will clear the codec gpio data when enter

2
sound/pci/hda/patch_via.c
View File

@ -396,7 +396,7 @@ static int via_resume(struct hda_codec *codec)
/* some delay here to make jack detection working (bko#98921) */
msleep(10);
codec->patch_ops.init(codec);
regcache_sync(codec->core.regmap);
snd_hda_regmap_sync(codec);
return 0;
}
#endif