target/linux/bcm27xx/patches-4.19/950-0372-staging-bcm2835-audio-Clean-up-mutex-locks.patch

   1 From 96588b9ccaddd69a832a07e2e3f2f3299e6d6c3a Mon Sep 17 00:00:00 2001
   2 From: Takashi Iwai <tiwai@suse.de>
   3 Date: Tue, 4 Sep 2018 17:58:30 +0200
   4 Subject: [PATCH] staging: bcm2835-audio: Clean up mutex locks
   5
   6 commit ce4bb1aa271a97047b80ac917a5d91b54925913b upstream.
   7
   8 snd-bcm2835 driver takes the lock with mutex_lock_interruptible() in
   9 all places, which don't make sense.  Replace them with the simple
  10 mutex_lock().
  11
  12 Also taking a mutex lock right after creating it for each PCM object
  13 is nonsense, too.  It cannot be racy at that point.  We can get rid of
  14 it.
  15
  16 Last but not least, initializing chip->audio_mutex at each place is
  17 error-prone.  Initialize properly at creating the chip object in
  18 snd_bcm2835_create() instead.
  19
  20 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  21 Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  23 ---
  24  .../vc04_services/bcm2835-audio/bcm2835-ctl.c | 18 +++----
  25  .../vc04_services/bcm2835-audio/bcm2835-pcm.c | 33 ++-----------
  26  .../bcm2835-audio/bcm2835-vchiq.c             | 47 ++++---------------
  27  .../vc04_services/bcm2835-audio/bcm2835.c     |  1 +
  28  4 files changed, 20 insertions(+), 79 deletions(-)
  29
  30 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-ctl.c
  31 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-ctl.c
  32 @@ -77,8 +77,7 @@ static int snd_bcm2835_ctl_get(struct sn
  33  {
  34         struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
  35
  36 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  37 -               return -EINTR;
  38 +       mutex_lock(&chip->audio_mutex);
  39
  40         BUG_ON(!chip && !(chip->avail_substreams & AVAIL_SUBSTREAMS_MASK));
  41
  42 @@ -99,8 +98,7 @@ static int snd_bcm2835_ctl_put(struct sn
  43         struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
  44         int changed = 0;
  45
  46 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  47 -               return -EINTR;
  48 +       mutex_lock(&chip->audio_mutex);
  49
  50         if (kcontrol->private_value == PCM_PLAYBACK_VOLUME) {
  51                 audio_info("Volume change attempted.. volume = %d new_volume = %d\n", chip->volume, (int)ucontrol->value.integer.value[0]);
  52 @@ -187,8 +185,7 @@ static int snd_bcm2835_spdif_default_get
  53         struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
  54         int i;
  55
  56 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  57 -               return -EINTR;
  58 +       mutex_lock(&chip->audio_mutex);
  59
  60         for (i = 0; i < 4; i++)
  61                 ucontrol->value.iec958.status[i] =
  62 @@ -205,8 +202,7 @@ static int snd_bcm2835_spdif_default_put
  63         unsigned int val = 0;
  64         int i, change;
  65
  66 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  67 -               return -EINTR;
  68 +       mutex_lock(&chip->audio_mutex);
  69
  70         for (i = 0; i < 4; i++)
  71                 val |= (unsigned int)ucontrol->value.iec958.status[i] << (i * 8);
  72 @@ -251,8 +247,7 @@ static int snd_bcm2835_spdif_stream_get(
  73         struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
  74         int i;
  75
  76 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  77 -               return -EINTR;
  78 +       mutex_lock(&chip->audio_mutex);
  79
  80         for (i = 0; i < 4; i++)
  81                 ucontrol->value.iec958.status[i] =
  82 @@ -269,8 +264,7 @@ static int snd_bcm2835_spdif_stream_put(
  83         unsigned int val = 0;
  84         int i, change;
  85
  86 -       if (mutex_lock_interruptible(&chip->audio_mutex))
  87 -               return -EINTR;
  88 +       mutex_lock(&chip->audio_mutex);
  89
  90         for (i = 0; i < 4; i++)
  91                 val |= (unsigned int)ucontrol->value.iec958.status[i] << (i * 8);
  92 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
  93 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
  94 @@ -99,10 +99,7 @@ static int snd_bcm2835_playback_open_gen
  95         int idx;
  96         int err;
  97
  98 -       if (mutex_lock_interruptible(&chip->audio_mutex)) {
  99 -               audio_error("Interrupted whilst waiting for lock\n");
 100 -               return -EINTR;
 101 -       }
 102 +       mutex_lock(&chip->audio_mutex);
 103         audio_info("Alsa open (%d)\n", substream->number);
 104         idx = substream->number;
 105
 106 @@ -194,10 +191,7 @@ static int snd_bcm2835_playback_close(st
 107         struct bcm2835_alsa_stream *alsa_stream;
 108
 109         chip = snd_pcm_substream_chip(substream);
 110 -       if (mutex_lock_interruptible(&chip->audio_mutex)) {
 111 -               audio_error("Interrupted whilst waiting for lock\n");
 112 -               return -EINTR;
 113 -       }
 114 +       mutex_lock(&chip->audio_mutex);
 115         runtime = substream->runtime;
 116         alsa_stream = runtime->private_data;
 117
 118 @@ -274,8 +268,7 @@ static int snd_bcm2835_pcm_prepare(struc
 119         int channels;
 120         int err;
 121
 122 -       if (mutex_lock_interruptible(&chip->audio_mutex))
 123 -               return -EINTR;
 124 +       mutex_lock(&chip->audio_mutex);
 125
 126         /* notify the vchiq that it should enter spdif passthrough mode by
 127          * setting channels=0 (see
 128 @@ -449,14 +442,9 @@ int snd_bcm2835_new_pcm(struct bcm2835_c
 129         struct snd_pcm *pcm;
 130         int err;
 131
 132 -       mutex_init(&chip->audio_mutex);
 133 -       if (mutex_lock_interruptible(&chip->audio_mutex)) {
 134 -               audio_error("Interrupted whilst waiting for lock\n");
 135 -               return -EINTR;
 136 -       }
 137         err = snd_pcm_new(chip->card, "bcm2835 ALSA", 0, numchannels, 0, &pcm);
 138         if (err < 0)
 139 -               goto out;
 140 +               return err;
 141         pcm->private_data = chip;
 142         strcpy(pcm->name, "bcm2835 ALSA");
 143         chip->pcm = pcm;
 144 @@ -474,9 +462,6 @@ int snd_bcm2835_new_pcm(struct bcm2835_c
 145                                               snd_bcm2835_playback_hw.buffer_bytes_max,
 146                                               snd_bcm2835_playback_hw.buffer_bytes_max);
 147
 148 -out:
 149 -       mutex_unlock(&chip->audio_mutex);
 150 -
 151         return 0;
 152  }
 153
 154 @@ -485,13 +470,9 @@ int snd_bcm2835_new_spdif_pcm(struct bcm
 155         struct snd_pcm *pcm;
 156         int err;
 157
 158 -       if (mutex_lock_interruptible(&chip->audio_mutex)) {
 159 -               audio_error("Interrupted whilst waiting for lock\n");
 160 -               return -EINTR;
 161 -       }
 162         err = snd_pcm_new(chip->card, "bcm2835 ALSA", 1, 1, 0, &pcm);
 163         if (err < 0)
 164 -               goto out;
 165 +               return err;
 166
 167         pcm->private_data = chip;
 168         strcpy(pcm->name, "bcm2835 IEC958/HDMI");
 169 @@ -504,8 +485,6 @@ int snd_bcm2835_new_spdif_pcm(struct bcm
 170         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 171                 snd_dma_continuous_data(GFP_KERNEL),
 172                 snd_bcm2835_playback_spdif_hw.buffer_bytes_max, snd_bcm2835_playback_spdif_hw.buffer_bytes_max);
 173 -out:
 174 -       mutex_unlock(&chip->audio_mutex);
 175
 176         return 0;
 177  }
 178 @@ -518,8 +497,6 @@ int snd_bcm2835_new_simple_pcm(struct bc
 179         struct snd_pcm *pcm;
 180         int err;
 181
 182 -       mutex_init(&chip->audio_mutex);
 183 -
 184         err = snd_pcm_new(chip->card, name, 0, numchannels,
 185                           0, &pcm);
 186         if (err)
 187 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
 188 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
 189 @@ -319,11 +319,7 @@ static int vc_vchi_audio_deinit(struct b
 190         }
 191
 192         LOG_DBG(" .. about to lock (%d)\n", instance->num_connections);
 193 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 194 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 195 -                       instance->num_connections);
 196 -               return -EINTR;
 197 -       }
 198 +       mutex_lock(&instance->vchi_mutex);
 199
 200         /* Close all VCHI service connections */
 201         for (i = 0; i < instance->num_connections; i++) {
 202 @@ -434,11 +430,7 @@ int bcm2835_audio_open(struct bcm2835_al
 203         instance = alsa_stream->instance;
 204         LOG_DBG(" instance (%p)\n", instance);
 205
 206 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 207 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
 208 -               ret = -EINTR;
 209 -               goto free_wq;
 210 -       }
 211 +       mutex_lock(&instance->vchi_mutex);
 212         vchi_service_use(instance->vchi_handle[0]);
 213
 214         m.type = VC_AUDIO_MSG_TYPE_OPEN;
 215 @@ -479,11 +471,7 @@ static int bcm2835_audio_set_ctls_chan(s
 216         LOG_INFO(" Setting ALSA dest(%d), volume(%d)\n",
 217                  chip->dest, chip->volume);
 218
 219 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 220 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 221 -                       instance->num_connections);
 222 -               return -EINTR;
 223 -       }
 224 +       mutex_lock(&instance->vchi_mutex);
 225         vchi_service_use(instance->vchi_handle[0]);
 226
 227         instance->result = -1;
 228 @@ -569,10 +557,7 @@ int bcm2835_audio_set_params(struct bcm2
 229                 return -EINVAL;
 230         }
 231
 232 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 233 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
 234 -               return -EINTR;
 235 -       }
 236 +       mutex_lock(&instance->vchi_mutex);
 237         vchi_service_use(instance->vchi_handle[0]);
 238
 239         instance->result = -1;
 240 @@ -629,11 +614,7 @@ static int bcm2835_audio_start_worker(st
 241         int status;
 242         int ret;
 243
 244 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 245 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 246 -                       instance->num_connections);
 247 -               return -EINTR;
 248 -       }
 249 +       mutex_lock(&instance->vchi_mutex);
 250         vchi_service_use(instance->vchi_handle[0]);
 251
 252         m.type = VC_AUDIO_MSG_TYPE_START;
 253 @@ -665,11 +646,7 @@ static int bcm2835_audio_stop_worker(str
 254         int status;
 255         int ret;
 256
 257 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 258 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 259 -                       instance->num_connections);
 260 -               return -EINTR;
 261 -       }
 262 +       mutex_lock(&instance->vchi_mutex);
 263         vchi_service_use(instance->vchi_handle[0]);
 264
 265         m.type = VC_AUDIO_MSG_TYPE_STOP;
 266 @@ -704,11 +681,7 @@ int bcm2835_audio_close(struct bcm2835_a
 267
 268         my_workqueue_quit(alsa_stream);
 269
 270 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 271 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 272 -                       instance->num_connections);
 273 -               return -EINTR;
 274 -       }
 275 +       mutex_lock(&instance->vchi_mutex);
 276         vchi_service_use(instance->vchi_handle[0]);
 277
 278         m.type = VC_AUDIO_MSG_TYPE_CLOSE;
 279 @@ -761,11 +734,7 @@ static int bcm2835_audio_write_worker(st
 280
 281         LOG_INFO(" Writing %d bytes from %p\n", count, src);
 282
 283 -       if (mutex_lock_interruptible(&instance->vchi_mutex)) {
 284 -               LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
 285 -                       instance->num_connections);
 286 -               return -EINTR;
 287 -       }
 288 +       mutex_lock(&instance->vchi_mutex);
 289         vchi_service_use(instance->vchi_handle[0]);
 290
 291         if (instance->peer_version == 0 &&
 292 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
 293 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
 294 @@ -149,6 +149,7 @@ static int snd_bcm2835_create(struct snd
 295                 return -ENOMEM;
 296
 297         chip->card = card;
 298 +       mutex_init(&chip->audio_mutex);
 299
 300         chip->vchi_ctx = devres_find(card->dev->parent,
 301                                      bcm2835_devm_free_vchi_ctx, NULL, NULL);