[PATCH 5.4 050/111] ALSA: hda: Manage concurrent reg access more properly
From: Greg Kroah-Hartman
Date: Tue May 26 2020 - 15:08:09 EST
From: Takashi Iwai <tiwai@xxxxxxx>
[ Upstream commit 1a462be52f4505a2719631fb5aa7bfdbd37bfd8d ]
In the commit 8e85def5723e ("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@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200109090104.26073-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/sound/hda_regmap.h | 3 +
include/sound/hdaudio.h | 1 +
sound/hda/hdac_device.c | 1 +
sound/hda/hdac_regmap.c | 142 +++++++++++++++++++++++++---------
sound/pci/hda/hda_codec.c | 30 +++----
sound/pci/hda/hda_generic.c | 2 +-
sound/pci/hda/hda_local.h | 2 +
sound/pci/hda/patch_hdmi.c | 2 +-
sound/pci/hda/patch_realtek.c | 4 +-
sound/pci/hda/patch_via.c | 2 +-
10 files changed, 135 insertions(+), 54 deletions(-)
diff --git a/include/sound/hda_regmap.h b/include/sound/hda_regmap.h
index 5141f8ffbb12..4c1b9bebbd60 100644
--- a/include/sound/hda_regmap.h
+++ b/include/sound/hda_regmap.h
@@ -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
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index fb9dce4c6928..44e57bcc4a57 100644
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -87,6 +87,7 @@ 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 */
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index 9f3e37511408..c946fd8beebc 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -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);
diff --git a/sound/hda/hdac_regmap.c b/sound/hda/hdac_regmap.c
index 286361ecd640..2596a881186f 100644
--- a/sound/hda/hdac_regmap.c
+++ b/sound/hda/hdac_regmap.c
@@ -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 (err < 0)
- return err;
- val |= orig & ~mask;
- if (val == orig)
- return 0;
- err = snd_hdac_regmap_write_raw(codec, reg, val);
+ 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;
- 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);
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 6cb72336433a..07c03c32715a 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -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)
diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
index fc001c64ef20..6815f9dc8545 100644
--- a/sound/pci/hda/hda_generic.c
+++ b/sound/pci/hda/hda_generic.c
@@ -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);
diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 3942e1b528d8..3dca65d79b02 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -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,
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index d48263d1f6a2..d41c91468ab3 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2359,7 +2359,7 @@ 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);
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index a0e7d711cbb5..499c8150ebb8 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -908,7 +908,7 @@ 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;
}
@@ -3756,7 +3756,7 @@ 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
diff --git a/sound/pci/hda/patch_via.c b/sound/pci/hda/patch_via.c
index b40d01e01832..7ef8f3105cdb 100644
--- a/sound/pci/hda/patch_via.c
+++ b/sound/pci/hda/patch_via.c
@@ -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
--
2.25.1