--- /dev/null
+From 96588b9ccaddd69a832a07e2e3f2f3299e6d6c3a Mon Sep 17 00:00:00 2001
+From: Takashi Iwai <tiwai@suse.de>
+Date: Tue, 4 Sep 2018 17:58:30 +0200
+Subject: [PATCH] staging: bcm2835-audio: Clean up mutex locks
+
+commit ce4bb1aa271a97047b80ac917a5d91b54925913b upstream.
+
+snd-bcm2835 driver takes the lock with mutex_lock_interruptible() in
+all places, which don't make sense. Replace them with the simple
+mutex_lock().
+
+Also taking a mutex lock right after creating it for each PCM object
+is nonsense, too. It cannot be racy at that point. We can get rid of
+it.
+
+Last but not least, initializing chip->audio_mutex at each place is
+error-prone. Initialize properly at creating the chip object in
+snd_bcm2835_create() instead.
+
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ .../vc04_services/bcm2835-audio/bcm2835-ctl.c | 18 +++----
+ .../vc04_services/bcm2835-audio/bcm2835-pcm.c | 33 ++-----------
+ .../bcm2835-audio/bcm2835-vchiq.c | 47 ++++---------------
+ .../vc04_services/bcm2835-audio/bcm2835.c | 1 +
+ 4 files changed, 20 insertions(+), 79 deletions(-)
+
+--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-ctl.c
++++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-ctl.c
+@@ -77,8 +77,7 @@ static int snd_bcm2835_ctl_get(struct sn
+ {
+ struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ BUG_ON(!chip && !(chip->avail_substreams & AVAIL_SUBSTREAMS_MASK));
+
+@@ -99,8 +98,7 @@ static int snd_bcm2835_ctl_put(struct sn
+ struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+ int changed = 0;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ if (kcontrol->private_value == PCM_PLAYBACK_VOLUME) {
+ audio_info("Volume change attempted.. volume = %d new_volume = %d\n", chip->volume, (int)ucontrol->value.integer.value[0]);
+@@ -187,8 +185,7 @@ static int snd_bcm2835_spdif_default_get
+ struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+ int i;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ for (i = 0; i < 4; i++)
+ ucontrol->value.iec958.status[i] =
+@@ -205,8 +202,7 @@ static int snd_bcm2835_spdif_default_put
+ unsigned int val = 0;
+ int i, change;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ for (i = 0; i < 4; i++)
+ val |= (unsigned int)ucontrol->value.iec958.status[i] << (i * 8);
+@@ -251,8 +247,7 @@ static int snd_bcm2835_spdif_stream_get(
+ struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+ int i;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ for (i = 0; i < 4; i++)
+ ucontrol->value.iec958.status[i] =
+@@ -269,8 +264,7 @@ static int snd_bcm2835_spdif_stream_put(
+ unsigned int val = 0;
+ int i, change;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ for (i = 0; i < 4; i++)
+ val |= (unsigned int)ucontrol->value.iec958.status[i] << (i * 8);
+--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
++++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
+@@ -99,10 +99,7 @@ static int snd_bcm2835_playback_open_gen
+ int idx;
+ int err;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex)) {
+- audio_error("Interrupted whilst waiting for lock\n");
+- return -EINTR;
+- }
++ mutex_lock(&chip->audio_mutex);
+ audio_info("Alsa open (%d)\n", substream->number);
+ idx = substream->number;
+
+@@ -194,10 +191,7 @@ static int snd_bcm2835_playback_close(st
+ struct bcm2835_alsa_stream *alsa_stream;
+
+ chip = snd_pcm_substream_chip(substream);
+- if (mutex_lock_interruptible(&chip->audio_mutex)) {
+- audio_error("Interrupted whilst waiting for lock\n");
+- return -EINTR;
+- }
++ mutex_lock(&chip->audio_mutex);
+ runtime = substream->runtime;
+ alsa_stream = runtime->private_data;
+
+@@ -274,8 +268,7 @@ static int snd_bcm2835_pcm_prepare(struc
+ int channels;
+ int err;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex))
+- return -EINTR;
++ mutex_lock(&chip->audio_mutex);
+
+ /* notify the vchiq that it should enter spdif passthrough mode by
+ * setting channels=0 (see
+@@ -449,14 +442,9 @@ int snd_bcm2835_new_pcm(struct bcm2835_c
+ struct snd_pcm *pcm;
+ int err;
+
+- mutex_init(&chip->audio_mutex);
+- if (mutex_lock_interruptible(&chip->audio_mutex)) {
+- audio_error("Interrupted whilst waiting for lock\n");
+- return -EINTR;
+- }
+ err = snd_pcm_new(chip->card, "bcm2835 ALSA", 0, numchannels, 0, &pcm);
+ if (err < 0)
+- goto out;
++ return err;
+ pcm->private_data = chip;
+ strcpy(pcm->name, "bcm2835 ALSA");
+ chip->pcm = pcm;
+@@ -474,9 +462,6 @@ int snd_bcm2835_new_pcm(struct bcm2835_c
+ snd_bcm2835_playback_hw.buffer_bytes_max,
+ snd_bcm2835_playback_hw.buffer_bytes_max);
+
+-out:
+- mutex_unlock(&chip->audio_mutex);
+-
+ return 0;
+ }
+
+@@ -485,13 +470,9 @@ int snd_bcm2835_new_spdif_pcm(struct bcm
+ struct snd_pcm *pcm;
+ int err;
+
+- if (mutex_lock_interruptible(&chip->audio_mutex)) {
+- audio_error("Interrupted whilst waiting for lock\n");
+- return -EINTR;
+- }
+ err = snd_pcm_new(chip->card, "bcm2835 ALSA", 1, 1, 0, &pcm);
+ if (err < 0)
+- goto out;
++ return err;
+
+ pcm->private_data = chip;
+ strcpy(pcm->name, "bcm2835 IEC958/HDMI");
+@@ -504,8 +485,6 @@ int snd_bcm2835_new_spdif_pcm(struct bcm
+ snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+ snd_dma_continuous_data(GFP_KERNEL),
+ snd_bcm2835_playback_spdif_hw.buffer_bytes_max, snd_bcm2835_playback_spdif_hw.buffer_bytes_max);
+-out:
+- mutex_unlock(&chip->audio_mutex);
+
+ return 0;
+ }
+@@ -518,8 +497,6 @@ int snd_bcm2835_new_simple_pcm(struct bc
+ struct snd_pcm *pcm;
+ int err;
+
+- mutex_init(&chip->audio_mutex);
+-
+ err = snd_pcm_new(chip->card, name, 0, numchannels,
+ 0, &pcm);
+ if (err)
+--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
++++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+@@ -319,11 +319,7 @@ static int vc_vchi_audio_deinit(struct b
+ }
+
+ LOG_DBG(" .. about to lock (%d)\n", instance->num_connections);
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+
+ /* Close all VCHI service connections */
+ for (i = 0; i < instance->num_connections; i++) {
+@@ -434,11 +430,7 @@ int bcm2835_audio_open(struct bcm2835_al
+ instance = alsa_stream->instance;
+ LOG_DBG(" instance (%p)\n", instance);
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
+- ret = -EINTR;
+- goto free_wq;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ m.type = VC_AUDIO_MSG_TYPE_OPEN;
+@@ -479,11 +471,7 @@ static int bcm2835_audio_set_ctls_chan(s
+ LOG_INFO(" Setting ALSA dest(%d), volume(%d)\n",
+ chip->dest, chip->volume);
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ instance->result = -1;
+@@ -569,10 +557,7 @@ int bcm2835_audio_set_params(struct bcm2
+ return -EINVAL;
+ }
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ instance->result = -1;
+@@ -629,11 +614,7 @@ static int bcm2835_audio_start_worker(st
+ int status;
+ int ret;
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ m.type = VC_AUDIO_MSG_TYPE_START;
+@@ -665,11 +646,7 @@ static int bcm2835_audio_stop_worker(str
+ int status;
+ int ret;
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ m.type = VC_AUDIO_MSG_TYPE_STOP;
+@@ -704,11 +681,7 @@ int bcm2835_audio_close(struct bcm2835_a
+
+ my_workqueue_quit(alsa_stream);
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ m.type = VC_AUDIO_MSG_TYPE_CLOSE;
+@@ -761,11 +734,7 @@ static int bcm2835_audio_write_worker(st
+
+ LOG_INFO(" Writing %d bytes from %p\n", count, src);
+
+- if (mutex_lock_interruptible(&instance->vchi_mutex)) {
+- LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
+- instance->num_connections);
+- return -EINTR;
+- }
++ mutex_lock(&instance->vchi_mutex);
+ vchi_service_use(instance->vchi_handle[0]);
+
+ if (instance->peer_version == 0 &&
+--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
++++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
+@@ -149,6 +149,7 @@ static int snd_bcm2835_create(struct snd
+ return -ENOMEM;
+
+ chip->card = card;
++ mutex_init(&chip->audio_mutex);
+
+ chip->vchi_ctx = devres_find(card->dev->parent,
+ bcm2835_devm_free_vchi_ctx, NULL, NULL);
projects / openwrt / openwrt.git / blobdiff