[ALSA] make control.c suspend aware

Modules: Control Midlevel

This patch prevents user-space apps from accessing the hardware via
control interface while the soundcard is suspended.
Signed-off-by: Giuliano Pochini <pochini@shiny.it>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/control.c

@@ -658,7 +658,11 @@ static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 
 	if (copy_from_user(&info, _info, sizeof(info)))
 		return -EFAULT;
-	result = snd_ctl_elem_info(ctl, &info);
+	snd_power_lock(ctl->card);
+	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0, NULL);
+	if (result >= 0)
+		result = snd_ctl_elem_info(ctl, &info);
+	snd_power_unlock(ctl->card);
 	if (result >= 0)
 		if (copy_to_user(_info, &info, sizeof(info)))
 			return -EFAULT;
@@ -708,7 +712,11 @@ static int snd_ctl_elem_read_user(struct snd_card *card,
 		kfree(control);
 		return -EFAULT;
 	}
-	result = snd_ctl_elem_read(card, control);
+	snd_power_lock(card);
+	result = snd_power_wait(card, SNDRV_CTL_POWER_D0, NULL);
+	if (result >= 0)
+		result = snd_ctl_elem_read(card, control);
+	snd_power_unlock(card);
 	if (result >= 0)
 		if (copy_to_user(_control, control, sizeof(*control)))
 			result = -EFAULT;
@@ -758,6 +766,7 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 				   struct snd_ctl_elem_value __user *_control)
 {
 	struct snd_ctl_elem_value *control;
+	struct snd_card *card;
 	int result;
 
 	control = kmalloc(sizeof(*control), GFP_KERNEL);
@@ -767,7 +776,12 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 		kfree(control);
 		return -EFAULT;
 	}
-	result = snd_ctl_elem_write(file->card, file, control);
+	card = file->card;
+	snd_power_lock(card);
+	result = snd_power_wait(card, SNDRV_CTL_POWER_D0, NULL);
+	if (result >= 0)
+		result = snd_ctl_elem_write(card, file, control);
+	snd_power_unlock(card);
 	if (result >= 0)
 		if (copy_to_user(_control, control, sizeof(*control)))
 			result = -EFAULT;

sound/core/control_compat.c

@@ -107,7 +107,13 @@ static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
 	 */
 	if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
 		goto error;
-	err = snd_ctl_elem_info(ctl, data);
+
+	snd_power_lock(ctl->card);
+	err = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0, NULL);
+	if (err >= 0)
+		err = snd_ctl_elem_info(ctl, data);
+	snd_power_unlock(ctl->card);
+
 	if (err < 0)
 		goto error;
 	/* restore info to 32bit */
@@ -286,9 +292,14 @@ static int snd_ctl_elem_read_user_compat(struct snd_card *card,
 
 	if ((err = copy_ctl_value_from_user(card, data, data32, &type, &count)) < 0)
 		goto error;
-	if ((err = snd_ctl_elem_read(card, data)) < 0)
-		goto error;
-	err = copy_ctl_value_to_user(data32, data, type, count);
+
+	snd_power_lock(card);
+	err = snd_power_wait(card, SNDRV_CTL_POWER_D0, NULL);
+	if (err >= 0)
+		err = snd_ctl_elem_read(card, data);
+	snd_power_unlock(card);
+	if (err >= 0)
+		err = copy_ctl_value_to_user(data32, data, type, count);
  error:
 	kfree(data);
 	return err;
@@ -298,17 +309,23 @@ static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
 					  struct snd_ctl_elem_value32 __user *data32)
 {
 	struct snd_ctl_elem_value *data;
+	struct snd_card *card = file->card;
 	int err, type, count;
 
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;
 
-	if ((err = copy_ctl_value_from_user(file->card, data, data32, &type, &count)) < 0)
-		goto error;
-	if ((err = snd_ctl_elem_write(file->card, file, data)) < 0)
+	if ((err = copy_ctl_value_from_user(card, data, data32, &type, &count)) < 0)
 		goto error;
-	err = copy_ctl_value_to_user(data32, data, type, count);
+
+	snd_power_lock(card);
+	err = snd_power_wait(card, SNDRV_CTL_POWER_D0, NULL);
+	if (err >= 0)
+		err = snd_ctl_elem_write(card, file, data);
+	snd_power_unlock(card);
+	if (err >= 0)
+		err = copy_ctl_value_to_user(data32, data, type, count);
  error:
 	kfree(data);
 	return err;