1 files changed, 149 insertions, 36 deletions

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 441405081195..481ab0e94ffa 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -823,8 +823,25 @@ static int choose_rate(struct snd_pcm_substream *substream,
 	return snd_pcm_hw_param_near(substream, params, SNDRV_PCM_HW_PARAM_RATE, best_rate, NULL);
 }
 
-static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream,
-				     bool trylock)
+/* parameter locking: returns immediately if tried during streaming */
+static int lock_params(struct snd_pcm_runtime *runtime)
+{
+	if (mutex_lock_interruptible(&runtime->oss.params_lock))
+		return -ERESTARTSYS;
+	if (atomic_read(&runtime->oss.rw_ref)) {
+		mutex_unlock(&runtime->oss.params_lock);
+		return -EBUSY;
+	}
+	return 0;
+}
+
+static void unlock_params(struct snd_pcm_runtime *runtime)
+{
+	mutex_unlock(&runtime->oss.params_lock);
+}
+
+/* call with params_lock held */
+static int snd_pcm_oss_change_params_locked(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_pcm_hw_params *params, *sparams;
@@ -838,11 +855,8 @@ static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream,
 	const struct snd_mask *sformat_mask;
 	struct snd_mask mask;
 
-	if (trylock) {
-		if (!(mutex_trylock(&runtime->oss.params_lock)))
-			return -EAGAIN;
-	} else if (mutex_lock_interruptible(&runtime->oss.params_lock))
-		return -ERESTARTSYS;
+	if (!runtime->oss.params)
+		return 0;
 	sw_params = kzalloc(sizeof(*sw_params), GFP_KERNEL);
 	params = kmalloc(sizeof(*params), GFP_KERNEL);
 	sparams = kmalloc(sizeof(*sparams), GFP_KERNEL);
@@ -1068,6 +1082,23 @@ failure:
 	kfree(sw_params);
 	kfree(params);
 	kfree(sparams);
+	return err;
+}
+
+/* this one takes the lock by itself */
+static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream,
+				     bool trylock)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+
+	if (trylock) {
+		if (!(mutex_trylock(&runtime->oss.params_lock)))
+			return -EAGAIN;
+	} else if (mutex_lock_interruptible(&runtime->oss.params_lock))
+		return -ERESTARTSYS;
+
+	err = snd_pcm_oss_change_params_locked(substream);
 	mutex_unlock(&runtime->oss.params_lock);
 	return err;
 }
@@ -1096,11 +1127,14 @@ static int snd_pcm_oss_get_active_substream(struct snd_pcm_oss_file *pcm_oss_fil
 	return 0;
 }
 
+/* call with params_lock held */
 static int snd_pcm_oss_prepare(struct snd_pcm_substream *substream)
 {
 	int err;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 
+	if (!runtime->oss.prepare)
+		return 0;
 	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL);
 	if (err < 0) {
 		pcm_dbg(substream->pcm,
@@ -1120,8 +1154,6 @@ static int snd_pcm_oss_make_ready(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime;
 	int err;
 
-	if (substream == NULL)
-		return 0;
 	runtime = substream->runtime;
 	if (runtime->oss.params) {
 		err = snd_pcm_oss_change_params(substream, false);
@@ -1129,6 +1161,29 @@ static int snd_pcm_oss_make_ready(struct snd_pcm_substream *substream)
 			return err;
 	}
 	if (runtime->oss.prepare) {
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
+		err = snd_pcm_oss_prepare(substream);
+		mutex_unlock(&runtime->oss.params_lock);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/* call with params_lock held */
+static int snd_pcm_oss_make_ready_locked(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+	runtime = substream->runtime;
+	if (runtime->oss.params) {
+		err = snd_pcm_oss_change_params_locked(substream);
+		if (err < 0)
+			return err;
+	}
+	if (runtime->oss.prepare) {
 		err = snd_pcm_oss_prepare(substream);
 		if (err < 0)
 			return err;
@@ -1332,13 +1387,15 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha
 	if (atomic_read(&substream->mmap_count))
 		return -ENXIO;
 
-	if ((tmp = snd_pcm_oss_make_ready(substream)) < 0)
-		return tmp;
+	atomic_inc(&runtime->oss.rw_ref);
 	while (bytes > 0) {
 		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
 			tmp = -ERESTARTSYS;
 			break;
 		}
+		tmp = snd_pcm_oss_make_ready_locked(substream);
+		if (tmp < 0)
+			goto err;
 		if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
 			tmp = bytes;
 			if (tmp + runtime->oss.buffer_used > runtime->oss.period_bytes)
@@ -1394,6 +1451,7 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha
 		}
 		tmp = 0;
 	}
+	atomic_dec(&runtime->oss.rw_ref);
 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
 }
 
@@ -1439,13 +1497,15 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use
 	if (atomic_read(&substream->mmap_count))
 		return -ENXIO;
 
-	if ((tmp = snd_pcm_oss_make_ready(substream)) < 0)
-		return tmp;
+	atomic_inc(&runtime->oss.rw_ref);
 	while (bytes > 0) {
 		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
 			tmp = -ERESTARTSYS;
 			break;
 		}
+		tmp = snd_pcm_oss_make_ready_locked(substream);
+		if (tmp < 0)
+			goto err;
 		if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
 			if (runtime->oss.buffer_used == 0) {
 				tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1);
@@ -1486,6 +1546,7 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use
 		}
 		tmp = 0;
 	}
+	atomic_dec(&runtime->oss.rw_ref);
 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
 }
 
@@ -1501,10 +1562,12 @@ static int snd_pcm_oss_reset(struct snd_pcm_oss_file *pcm_oss_file)
 			continue;
 		runtime = substream->runtime;
 		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
+		mutex_lock(&runtime->oss.params_lock);
 		runtime->oss.prepare = 1;
 		runtime->oss.buffer_used = 0;
 		runtime->oss.prev_hw_ptr_period = 0;
 		runtime->oss.period_ptr = 0;
+		mutex_unlock(&runtime->oss.params_lock);
 	}
 	return 0;
 }
@@ -1590,9 +1653,13 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 			goto __direct;
 		if ((err = snd_pcm_oss_make_ready(substream)) < 0)
 			return err;
+		atomic_inc(&runtime->oss.rw_ref);
+		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
+			atomic_dec(&runtime->oss.rw_ref);
+			return -ERESTARTSYS;
+		}
 		format = snd_pcm_oss_format_from(runtime->oss.format);
 		width = snd_pcm_format_physical_width(format);
-		mutex_lock(&runtime->oss.params_lock);
 		if (runtime->oss.buffer_used > 0) {
 #ifdef OSS_DEBUG
 			pcm_dbg(substream->pcm, "sync: buffer_used\n");
@@ -1602,10 +1669,8 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 						   runtime->oss.buffer + runtime->oss.buffer_used,
 						   size);
 			err = snd_pcm_oss_sync1(substream, runtime->oss.period_bytes);
-			if (err < 0) {
-				mutex_unlock(&runtime->oss.params_lock);
-				return err;
-			}
+			if (err < 0)
+				goto unlock;
 		} else if (runtime->oss.period_ptr > 0) {
 #ifdef OSS_DEBUG
 			pcm_dbg(substream->pcm, "sync: period_ptr\n");
@@ -1615,10 +1680,8 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 						   runtime->oss.buffer,
 						   size * 8 / width);
 			err = snd_pcm_oss_sync1(substream, size);
-			if (err < 0) {
-				mutex_unlock(&runtime->oss.params_lock);
-				return err;
-			}
+			if (err < 0)
+				goto unlock;
 		}
 		/*
 		 * The ALSA's period might be a bit large than OSS one.
@@ -1632,7 +1695,11 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 			else if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
 				snd_pcm_lib_writev(substream, NULL, size);
 		}
+unlock:
 		mutex_unlock(&runtime->oss.params_lock);
+		atomic_dec(&runtime->oss.rw_ref);
+		if (err < 0)
+			return err;
 		/*
 		 * finish sync: drain the buffer
 		 */
@@ -1643,7 +1710,9 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 		substream->f_flags = saved_f_flags;
 		if (err < 0)
 			return err;
+		mutex_lock(&runtime->oss.params_lock);
 		runtime->oss.prepare = 1;
+		mutex_unlock(&runtime->oss.params_lock);
 	}
 
 	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
@@ -1654,8 +1723,10 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
 		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
 		if (err < 0)
 			return err;
+		mutex_lock(&runtime->oss.params_lock);
 		runtime->oss.buffer_used = 0;
 		runtime->oss.prepare = 1;
+		mutex_unlock(&runtime->oss.params_lock);
 	}
 	return 0;
 }
@@ -1667,6 +1738,8 @@ static int snd_pcm_oss_set_rate(struct snd_pcm_oss_file *pcm_oss_file, int rate)
 	for (idx = 1; idx >= 0; --idx) {
 		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
 		struct snd_pcm_runtime *runtime;
+		int err;
+
 		if (substream == NULL)
 			continue;
 		runtime = substream->runtime;
@@ -1674,10 +1747,14 @@ static int snd_pcm_oss_set_rate(struct snd_pcm_oss_file *pcm_oss_file, int rate)
 			rate = 1000;
 		else if (rate > 192000)
 			rate = 192000;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
 		if (runtime->oss.rate != rate) {
 			runtime->oss.params = 1;
 			runtime->oss.rate = rate;
 		}
+		unlock_params(runtime);
 	}
 	return snd_pcm_oss_get_rate(pcm_oss_file);
 }
@@ -1702,13 +1779,19 @@ static int snd_pcm_oss_set_channels(struct snd_pcm_oss_file *pcm_oss_file, unsig
 	for (idx = 1; idx >= 0; --idx) {
 		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
 		struct snd_pcm_runtime *runtime;
+		int err;
+
 		if (substream == NULL)
 			continue;
 		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
 		if (runtime->oss.channels != channels) {
 			runtime->oss.params = 1;
 			runtime->oss.channels = channels;
 		}
+		unlock_params(runtime);
 	}
 	return snd_pcm_oss_get_channels(pcm_oss_file);
 }
@@ -1781,6 +1864,7 @@ static int snd_pcm_oss_get_formats(struct snd_pcm_oss_file *pcm_oss_file)
 static int snd_pcm_oss_set_format(struct snd_pcm_oss_file *pcm_oss_file, int format)
 {
 	int formats, idx;
+	int err;
 	
 	if (format != AFMT_QUERY) {
 		formats = snd_pcm_oss_get_formats(pcm_oss_file);
@@ -1794,10 +1878,14 @@ static int snd_pcm_oss_set_format(struct snd_pcm_oss_file *pcm_oss_file, int for
 			if (substream == NULL)
 				continue;
 			runtime = substream->runtime;
+			err = lock_params(runtime);
+			if (err < 0)
+				return err;
 			if (runtime->oss.format != format) {
 				runtime->oss.params = 1;
 				runtime->oss.format = format;
 			}
+			unlock_params(runtime);
 		}
 	}
 	return snd_pcm_oss_get_format(pcm_oss_file);
@@ -1817,8 +1905,6 @@ static int snd_pcm_oss_set_subdivide1(struct snd_pcm_substream *substream, int s
 {
 	struct snd_pcm_runtime *runtime;
 
-	if (substream == NULL)
-		return 0;
 	runtime = substream->runtime;
 	if (subdivide == 0) {
 		subdivide = runtime->oss.subdivision;
@@ -1842,9 +1928,17 @@ static int snd_pcm_oss_set_subdivide(struct snd_pcm_oss_file *pcm_oss_file, int
 
 	for (idx = 1; idx >= 0; --idx) {
 		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+
 		if (substream == NULL)
 			continue;
-		if ((err = snd_pcm_oss_set_subdivide1(substream, subdivide)) < 0)
+		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		err = snd_pcm_oss_set_subdivide1(substream, subdivide);
+		unlock_params(runtime);
+		if (err < 0)
 			return err;
 	}
 	return err;
@@ -1854,8 +1948,6 @@ static int snd_pcm_oss_set_fragment1(struct snd_pcm_substream *substream, unsign
 {
 	struct snd_pcm_runtime *runtime;
 
-	if (substream == NULL)
-		return 0;
 	runtime = substream->runtime;
 	if (runtime->oss.subdivision || runtime->oss.fragshift)
 		return -EINVAL;
@@ -1875,9 +1967,17 @@ static int snd_pcm_oss_set_fragment(struct snd_pcm_oss_file *pcm_oss_file, unsig
 
 	for (idx = 1; idx >= 0; --idx) {
 		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+
 		if (substream == NULL)
 			continue;
-		if ((err = snd_pcm_oss_set_fragment1(substream, val)) < 0)
+		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		err = snd_pcm_oss_set_fragment1(substream, val);
+		unlock_params(runtime);
+		if (err < 0)
 			return err;
 	}
 	return err;
@@ -1961,6 +2061,9 @@ static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int tr
 	}
       	if (psubstream) {
       		runtime = psubstream->runtime;
+		cmd = 0;
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
 		if (trigger & PCM_ENABLE_OUTPUT) {
 			if (runtime->oss.trigger)
 				goto _skip1;
@@ -1978,13 +2081,19 @@ static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int tr
 			cmd = SNDRV_PCM_IOCTL_DROP;
 			runtime->oss.prepare = 1;
 		}
-		err = snd_pcm_kernel_ioctl(psubstream, cmd, NULL);
-		if (err < 0)
-			return err;
-	}
  _skip1:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (cmd) {
+			err = snd_pcm_kernel_ioctl(psubstream, cmd, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
 	if (csubstream) {
       		runtime = csubstream->runtime;
+		cmd = 0;
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
 		if (trigger & PCM_ENABLE_INPUT) {
 			if (runtime->oss.trigger)
 				goto _skip2;
@@ -1999,11 +2108,14 @@ static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int tr
 			cmd = SNDRV_PCM_IOCTL_DROP;
 			runtime->oss.prepare = 1;
 		}
-		err = snd_pcm_kernel_ioctl(csubstream, cmd, NULL);
-		if (err < 0)
-			return err;
-	}
  _skip2:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (cmd) {
+			err = snd_pcm_kernel_ioctl(csubstream, cmd, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
 	return 0;
 }
 
@@ -2255,6 +2367,7 @@ static void snd_pcm_oss_init_substream(struct snd_pcm_substream *substream,
 	runtime->oss.maxfrags = 0;
 	runtime->oss.subdivision = 0;
 	substream->pcm_release = snd_pcm_oss_release_substream;
+	atomic_set(&runtime->oss.rw_ref, 0);
 }
 
 static int snd_pcm_oss_release_file(struct snd_pcm_oss_file *pcm_oss_file)