[ALSA] aoa: add locking to tas codec

Looks like I completely forgot to do this. This patch adds locking to
the tas codec so two userspace programs can't hit the controls at the
same time. Tested on my powerbook, but I obviously can't find any
problems even without it since it doesn't do SMP.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 83 insertions, 13 deletions

diff --git a/sound/aoa/codecs/snd-aoa-codec-tas.c b/sound/aoa/codecs/snd-aoa-codec-tas.c
index 16c0b6b0a805..2ef55a17917c 100644
--- a/sound/aoa/codecs/snd-aoa-codec-tas.c
+++ b/sound/aoa/codecs/snd-aoa-codec-tas.c
@@ -66,6 +66,8 @@
 #include <asm/prom.h>
 #include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
+
 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("tas codec driver for snd-aoa");
@@ -91,6 +93,10 @@ struct tas {
         u8                      bass, treble;
         u8                      acr;
         int                     drc_range;
+        /* protects hardware access against concurrency from
+         * userspace when hitting controls and during
+         * codec init/suspend/resume */
+        struct mutex            mtx;
 };
 
 static int tas_reset_init(struct tas *tas);
@@ -231,8 +237,10 @@ static int tas_snd_vol_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->cached_volume_l;
         ucontrol->value.integer.value[1] = tas->cached_volume_r;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -241,14 +249,18 @@ static int tas_snd_vol_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         if (tas->cached_volume_l == ucontrol->value.integer.value[0]
-         && tas->cached_volume_r == ucontrol->value.integer.value[1])
+         && tas->cached_volume_r == ucontrol->value.integer.value[1]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->cached_volume_l = ucontrol->value.integer.value[0];
         tas->cached_volume_r = ucontrol->value.integer.value[1];
         if (tas->hw_enabled)
                 tas_set_volume(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -276,8 +288,10 @@ static int tas_snd_mute_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = !tas->mute_l;
         ucontrol->value.integer.value[1] = !tas->mute_r;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -286,14 +300,18 @@ static int tas_snd_mute_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         if (tas->mute_l == !ucontrol->value.integer.value[0]
-         && tas->mute_r == !ucontrol->value.integer.value[1])
+         && tas->mute_r == !ucontrol->value.integer.value[1]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->mute_l = !ucontrol->value.integer.value[0];
         tas->mute_r = !ucontrol->value.integer.value[1];
         if (tas->hw_enabled)
                 tas_set_volume(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -322,8 +340,10 @@ static int tas_snd_mixer_get(struct snd_kcontrol *kcontrol,
         struct tas *tas = snd_kcontrol_chip(kcontrol);
         int idx = kcontrol->private_value;
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->mixer_l[idx];
         ucontrol->value.integer.value[1] = tas->mixer_r[idx];
+        mutex_unlock(&tas->mtx);
 
         return 0;
 }
@@ -334,15 +354,19 @@ static int tas_snd_mixer_put(struct snd_kcontrol *kcontrol,
         struct tas *tas = snd_kcontrol_chip(kcontrol);
         int idx = kcontrol->private_value;
 
+        mutex_lock(&tas->mtx);
         if (tas->mixer_l[idx] == ucontrol->value.integer.value[0]
-         && tas->mixer_r[idx] == ucontrol->value.integer.value[1])
+         && tas->mixer_r[idx] == ucontrol->value.integer.value[1]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->mixer_l[idx] = ucontrol->value.integer.value[0];
         tas->mixer_r[idx] = ucontrol->value.integer.value[1];
 
         if (tas->hw_enabled)
                 tas_set_mixer(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -375,7 +399,9 @@ static int tas_snd_drc_range_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->drc_range;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -384,12 +410,16 @@ static int tas_snd_drc_range_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
-        if (tas->drc_range == ucontrol->value.integer.value[0])
+        mutex_lock(&tas->mtx);
+        if (tas->drc_range == ucontrol->value.integer.value[0]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->drc_range = ucontrol->value.integer.value[0];
         if (tas->hw_enabled)
                 tas3004_set_drc(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -417,7 +447,9 @@ static int tas_snd_drc_switch_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->drc_enabled;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -426,12 +458,16 @@ static int tas_snd_drc_switch_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
-        if (tas->drc_enabled == ucontrol->value.integer.value[0])
+        mutex_lock(&tas->mtx);
+        if (tas->drc_enabled == ucontrol->value.integer.value[0]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->drc_enabled = ucontrol->value.integer.value[0];
         if (tas->hw_enabled)
                 tas3004_set_drc(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -463,7 +499,9 @@ static int tas_snd_capture_source_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.enumerated.item[0] = !!(tas->acr & TAS_ACR_INPUT_B);
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -471,15 +509,21 @@ static int tas_snd_capture_source_put(struct snd_kcontrol *kcontrol,
         struct snd_ctl_elem_value *ucontrol)
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
-        int oldacr = tas->acr;
+        int oldacr;
+
+        mutex_lock(&tas->mtx);
+        oldacr = tas->acr;
 
         tas->acr &= ~TAS_ACR_INPUT_B;
         if (ucontrol->value.enumerated.item[0])
                 tas->acr |= TAS_ACR_INPUT_B;
-        if (oldacr == tas->acr)
+        if (oldacr == tas->acr) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
         if (tas->hw_enabled)
                 tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -518,7 +562,9 @@ static int tas_snd_treble_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->treble;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -527,12 +573,16 @@ static int tas_snd_treble_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
-        if (tas->treble == ucontrol->value.integer.value[0])
+        mutex_lock(&tas->mtx);
+        if (tas->treble == ucontrol->value.integer.value[0]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->treble = ucontrol->value.integer.value[0];
         if (tas->hw_enabled)
                 tas_set_treble(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -560,7 +610,9 @@ static int tas_snd_bass_get(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
+        mutex_lock(&tas->mtx);
         ucontrol->value.integer.value[0] = tas->bass;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -569,12 +621,16 @@ static int tas_snd_bass_put(struct snd_kcontrol *kcontrol,
 {
         struct tas *tas = snd_kcontrol_chip(kcontrol);
 
-        if (tas->bass == ucontrol->value.integer.value[0])
+        mutex_lock(&tas->mtx);
+        if (tas->bass == ucontrol->value.integer.value[0]) {
+                mutex_unlock(&tas->mtx);
                 return 0;
+        }
 
         tas->bass = ucontrol->value.integer.value[0];
         if (tas->hw_enabled)
                 tas_set_bass(tas);
+        mutex_unlock(&tas->mtx);
         return 1;
 }
 
@@ -628,16 +684,16 @@ static int tas_reset_init(struct tas *tas)
 
         tmp = TAS_MCS_SCLK64 | TAS_MCS_SPORT_MODE_I2S | TAS_MCS_SPORT_WL_24BIT;
         if (tas_write_reg(tas, TAS_REG_MCS, 1, &tmp))
-                return -ENODEV;
+                goto outerr;
 
         tas->acr |= TAS_ACR_ANALOG_PDOWN | TAS_ACR_B_MONAUREAL |
                 TAS_ACR_B_MON_SEL_RIGHT;
         if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
-                return -ENODEV;
+                goto outerr;
 
         tmp = 0;
         if (tas_write_reg(tas, TAS_REG_MCS2, 1, &tmp))
-                return -ENODEV;
+                goto outerr;
 
         tas3004_set_drc(tas);
 
@@ -649,9 +705,11 @@ static int tas_reset_init(struct tas *tas)
 
         tas->acr &= ~TAS_ACR_ANALOG_PDOWN;
         if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
-                return -ENODEV;
+                goto outerr;
 
         return 0;
+ outerr:
+        return -ENODEV;
 }
 
 static int tas_switch_clock(struct codec_info_item *cii, enum clock_switch clock)
@@ -666,11 +724,13 @@ static int tas_switch_clock(struct codec_info_item *cii, enum clock_switch clock
                 break;
         case CLOCK_SWITCH_SLAVE:
                 /* Clocks are back, re-init the codec */
+                mutex_lock(&tas->mtx);
                 tas_reset_init(tas);
                 tas_set_volume(tas);
                 tas_set_mixer(tas);
                 tas->hw_enabled = 1;
                 tas->codec.gpio->methods->all_amps_restore(tas->codec.gpio);
+                mutex_unlock(&tas->mtx);
                 break;
         default:
                 /* doesn't happen as of now */
@@ -684,19 +744,23 @@ static int tas_switch_clock(struct codec_info_item *cii, enum clock_switch clock
  * our i2c device is suspended, and then take note of that! */
 static int tas_suspend(struct tas *tas)
 {
+        mutex_lock(&tas->mtx);
         tas->hw_enabled = 0;
         tas->acr |= TAS_ACR_ANALOG_PDOWN;
         tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
 static int tas_resume(struct tas *tas)
 {
         /* reset codec */
+        mutex_lock(&tas->mtx);
         tas_reset_init(tas);
         tas_set_volume(tas);
         tas_set_mixer(tas);
         tas->hw_enabled = 1;
+        mutex_unlock(&tas->mtx);
         return 0;
 }
 
@@ -739,11 +803,14 @@ static int tas_init_codec(struct aoa_codec *codec)
                 return -EINVAL;
         }
 
+        mutex_lock(&tas->mtx);
         if (tas_reset_init(tas)) {
                 printk(KERN_ERR PFX "tas failed to initialise\n");
+                mutex_unlock(&tas->mtx);
                 return -ENXIO;
         }
         tas->hw_enabled = 1;
+        mutex_unlock(&tas->mtx);
 
         if (tas->codec.soundbus_dev->attach_codec(tas->codec.soundbus_dev,
                                                    aoa_get_card(),
@@ -822,6 +889,7 @@ static int tas_create(struct i2c_adapter *adapter,
         if (!tas)
                 return -ENOMEM;
 
+        mutex_init(&tas->mtx);
         tas->i2c.driver = &tas_driver;
         tas->i2c.adapter = adapter;
         tas->i2c.addr = addr;
@@ -850,6 +918,7 @@ static int tas_create(struct i2c_adapter *adapter,
  detach:
         i2c_detach_client(&tas->i2c);
  fail:
+        mutex_destroy(&tas->mtx);
         kfree(tas);
         return -EINVAL;
 }
@@ -908,6 +977,7 @@ static int tas_i2c_detach(struct i2c_client *client)
         /* power down codec chip */
         tas_write_reg(tas, TAS_REG_ACR, 1, &tmp);
 
+        mutex_destroy(&tas->mtx);
         kfree(tas);
         return 0;
 }