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authorHans-Christian Egtvedt <hcegtvedt@atmel.com>2007-12-17 17:30:06 +0100
committerJaroslav Kysela <perex@perex.cz>2008-01-31 17:29:39 +0100
commitf488d9fcc84692ca0060b4e16c1c61a8d514cea8 (patch)
tree701cfaeb3f883a6cc7cfc65356c03d7221e55237 /sound/spi
parentac3e37412c195f1b48fe06327eb4ad0c072a1222 (diff)
downloadlinux-linaro-stable-f488d9fcc84692ca0060b4e16c1c61a8d514cea8.tar.gz
[ALSA] at73c213: replace spinlock in mixer functions with a mutex
This patch fixes the locking bug in the at73c213 SPI sound driver. This bug was triggered because spinlocks were wrapped around the spi_sync call which might sleep. The fix was to add a mutex to the sound driver and replace the spinlocks in the mixer functions with mutex lock/unlock. Tested on STK1000/STK1002. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Diffstat (limited to 'sound/spi')
-rw-r--r--sound/spi/at73c213.c34
1 files changed, 19 insertions, 15 deletions
diff --git a/sound/spi/at73c213.c b/sound/spi/at73c213.c
index bfe17b3ec8f4..5e8cf9f44ca3 100644
--- a/sound/spi/at73c213.c
+++ b/sound/spi/at73c213.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/io.h>
@@ -76,8 +77,10 @@ struct snd_at73c213 {
u8 spi_rbuffer[2];
/* Image of the SPI registers in AT73C213. */
u8 reg_image[18];
- /* Protect registers against concurrent access. */
+ /* Protect SSC registers against concurrent access. */
spinlock_t lock;
+ /* Protect mixer registers against concurrent access. */
+ struct mutex mixer_lock;
};
#define get_chip(card) ((struct snd_at73c213 *)card->private_data)
@@ -398,7 +401,7 @@ static int snd_at73c213_mono_get(struct snd_kcontrol *kcontrol,
int mask = (kcontrol->private_value >> 16) & 0xff;
int invert = (kcontrol->private_value >> 24) & 0xff;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
ucontrol->value.integer.value[0] =
(chip->reg_image[reg] >> shift) & mask;
@@ -407,7 +410,7 @@ static int snd_at73c213_mono_get(struct snd_kcontrol *kcontrol,
ucontrol->value.integer.value[0] =
mask - ucontrol->value.integer.value[0];
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
return 0;
}
@@ -428,13 +431,13 @@ static int snd_at73c213_mono_put(struct snd_kcontrol *kcontrol,
val = mask - val;
val <<= shift;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
val = (chip->reg_image[reg] & ~(mask << shift)) | val;
change = val != chip->reg_image[reg];
retval = snd_at73c213_write_reg(chip, reg, val);
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
if (retval)
return retval;
@@ -470,7 +473,7 @@ static int snd_at73c213_stereo_get(struct snd_kcontrol *kcontrol,
int mask = (kcontrol->private_value >> 24) & 0xff;
int invert = (kcontrol->private_value >> 22) & 1;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
ucontrol->value.integer.value[0] =
(chip->reg_image[left_reg] >> shift_left) & mask;
@@ -484,7 +487,7 @@ static int snd_at73c213_stereo_get(struct snd_kcontrol *kcontrol,
mask - ucontrol->value.integer.value[1];
}
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
return 0;
}
@@ -511,7 +514,7 @@ static int snd_at73c213_stereo_put(struct snd_kcontrol *kcontrol,
val1 <<= shift_left;
val2 <<= shift_right;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
val1 = (chip->reg_image[left_reg] & ~(mask << shift_left)) | val1;
val2 = (chip->reg_image[right_reg] & ~(mask << shift_right)) | val2;
@@ -519,16 +522,16 @@ static int snd_at73c213_stereo_put(struct snd_kcontrol *kcontrol,
|| val2 != chip->reg_image[right_reg];
retval = snd_at73c213_write_reg(chip, left_reg, val1);
if (retval) {
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
goto out;
}
retval = snd_at73c213_write_reg(chip, right_reg, val2);
if (retval) {
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
goto out;
}
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
return change;
@@ -546,7 +549,7 @@ static int snd_at73c213_mono_switch_get(struct snd_kcontrol *kcontrol,
int shift = (kcontrol->private_value >> 8) & 0xff;
int invert = (kcontrol->private_value >> 24) & 0xff;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
ucontrol->value.integer.value[0] =
(chip->reg_image[reg] >> shift) & 0x01;
@@ -555,7 +558,7 @@ static int snd_at73c213_mono_switch_get(struct snd_kcontrol *kcontrol,
ucontrol->value.integer.value[0] =
0x01 - ucontrol->value.integer.value[0];
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
return 0;
}
@@ -580,14 +583,14 @@ static int snd_at73c213_mono_switch_put(struct snd_kcontrol *kcontrol,
val = mask - val;
val <<= shift;
- spin_lock_irq(&chip->lock);
+ mutex_lock(&chip->mixer_lock);
val |= (chip->reg_image[reg] & ~(mask << shift));
change = val != chip->reg_image[reg];
retval = snd_at73c213_write_reg(chip, reg, val);
- spin_unlock_irq(&chip->lock);
+ mutex_unlock(&chip->mixer_lock);
if (retval)
return retval;
@@ -884,6 +887,7 @@ static int __devinit snd_at73c213_dev_init(struct snd_card *card,
return irq;
spin_lock_init(&chip->lock);
+ mutex_init(&chip->mixer_lock);
chip->card = card;
chip->irq = -1;