[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>

diff --git a/sound/aoa/codecs/snd-aoa-codec-tas.c b/sound/aoa/codecs/snd-aoa-codec-tas.c
index 16c0b6b0a80521eb90134bf50acfa46b842c9b0e..2ef55a17917c64999740b02780e035b2457429c2 100644 (file)
--- 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;
 }