lkml.org 
[lkml]   [2012]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 023/241] ALSA: usb-audio: Use rwsem for disconnect protection
    Date
    3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Takashi Iwai <tiwai@suse.de>

    commit 34f3c89fda4fba9fe689db22253ca8db2f5e6386 upstream.

    Replace mutex with rwsem for codec->shutdown protection so that
    concurrent accesses are allowed.

    Also add the protection to snd_usb_autosuspend() and
    snd_usb_autoresume(), too.

    Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
    Signed-off-by: Takashi Iwai <tiwai@suse.de>
    [ herton: verified and applied version for 3.6.y ]
    Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
    ---
    sound/usb/card.c | 12 ++++++++----
    sound/usb/mixer.c | 12 ++++++------
    sound/usb/pcm.c | 12 ++++++------
    sound/usb/usbaudio.h | 2 +-
    4 files changed, 21 insertions(+), 17 deletions(-)

    diff --git a/sound/usb/card.c b/sound/usb/card.c
    index 4a469f0..486b4a6 100644
    --- a/sound/usb/card.c
    +++ b/sound/usb/card.c
    @@ -339,7 +339,7 @@ static int snd_usb_audio_create(struct usb_device *dev, int idx,
    }

    mutex_init(&chip->mutex);
    - mutex_init(&chip->shutdown_mutex);
    + init_rwsem(&chip->shutdown_rwsem);
    chip->index = idx;
    chip->dev = dev;
    chip->card = card;
    @@ -560,7 +560,7 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,

    card = chip->card;
    mutex_lock(&register_mutex);
    - mutex_lock(&chip->shutdown_mutex);
    + down_write(&chip->shutdown_rwsem);
    chip->shutdown = 1;
    chip->num_interfaces--;
    if (chip->num_interfaces <= 0) {
    @@ -582,11 +582,11 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
    snd_usb_mixer_disconnect(p);
    }
    usb_chip[chip->index] = NULL;
    - mutex_unlock(&chip->shutdown_mutex);
    + up_write(&chip->shutdown_rwsem);
    mutex_unlock(&register_mutex);
    snd_card_free_when_closed(card);
    } else {
    - mutex_unlock(&chip->shutdown_mutex);
    + up_write(&chip->shutdown_rwsem);
    mutex_unlock(&register_mutex);
    }
    }
    @@ -618,16 +618,20 @@ int snd_usb_autoresume(struct snd_usb_audio *chip)
    {
    int err = -ENODEV;

    + down_read(&chip->shutdown_rwsem);
    if (!chip->shutdown && !chip->probing)
    err = usb_autopm_get_interface(chip->pm_intf);
    + up_read(&chip->shutdown_rwsem);

    return err;
    }

    void snd_usb_autosuspend(struct snd_usb_audio *chip)
    {
    + down_read(&chip->shutdown_rwsem);
    if (!chip->shutdown && !chip->probing)
    usb_autopm_put_interface(chip->pm_intf);
    + up_read(&chip->shutdown_rwsem);
    }

    static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
    diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
    index c2ef11c..298070e 100644
    --- a/sound/usb/mixer.c
    +++ b/sound/usb/mixer.c
    @@ -292,7 +292,7 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
    err = snd_usb_autoresume(cval->mixer->chip);
    if (err < 0)
    return -EIO;
    - mutex_lock(&chip->shutdown_mutex);
    + down_read(&chip->shutdown_rwsem);
    while (timeout-- > 0) {
    if (chip->shutdown)
    break;
    @@ -310,7 +310,7 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
    err = -EINVAL;

    out:
    - mutex_unlock(&chip->shutdown_mutex);
    + up_read(&chip->shutdown_rwsem);
    snd_usb_autosuspend(cval->mixer->chip);
    return err;
    }
    @@ -337,7 +337,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
    if (ret)
    goto error;

    - mutex_lock(&chip->shutdown_mutex);
    + down_read(&chip->shutdown_rwsem);
    if (chip->shutdown)
    ret = -ENODEV;
    else {
    @@ -346,7 +346,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
    validx, idx, buf, size);
    }
    - mutex_unlock(&chip->shutdown_mutex);
    + up_read(&chip->shutdown_rwsem);
    snd_usb_autosuspend(chip);

    if (ret < 0) {
    @@ -453,7 +453,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
    err = snd_usb_autoresume(chip);
    if (err < 0)
    return -EIO;
    - mutex_lock(&chip->shutdown_mutex);
    + down_read(&chip->shutdown_rwsem);
    while (timeout-- > 0) {
    if (chip->shutdown)
    break;
    @@ -471,7 +471,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
    err = -EINVAL;

    out:
    - mutex_unlock(&chip->shutdown_mutex);
    + up_read(&chip->shutdown_rwsem);
    snd_usb_autosuspend(chip);
    return err;
    }
    diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
    index 0de406a..ee3c15c 100644
    --- a/sound/usb/pcm.c
    +++ b/sound/usb/pcm.c
    @@ -474,7 +474,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
    subs->period_bytes != params_period_bytes(hw_params) ||
    subs->cur_rate != rate;

    - mutex_lock(&subs->stream->chip->shutdown_mutex);
    + down_read(&subs->stream->chip->shutdown_rwsem);
    if (subs->stream->chip->shutdown) {
    ret = -ENODEV;
    goto unlock;
    @@ -512,7 +512,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
    }

    unlock:
    - mutex_unlock(&subs->stream->chip->shutdown_mutex);
    + up_read(&subs->stream->chip->shutdown_rwsem);
    return ret;
    }

    @@ -528,12 +528,12 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
    subs->cur_audiofmt = NULL;
    subs->cur_rate = 0;
    subs->period_bytes = 0;
    - mutex_lock(&subs->stream->chip->shutdown_mutex);
    + down_read(&subs->stream->chip->shutdown_rwsem);
    if (!subs->stream->chip->shutdown) {
    stop_endpoints(subs, 0, 1, 1);
    deactivate_endpoints(subs);
    }
    - mutex_unlock(&subs->stream->chip->shutdown_mutex);
    + up_read(&subs->stream->chip->shutdown_rwsem);
    return snd_pcm_lib_free_vmalloc_buffer(substream);
    }

    @@ -553,7 +553,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
    return -ENXIO;
    }

    - mutex_lock(&subs->stream->chip->shutdown_mutex);
    + down_read(&subs->stream->chip->shutdown_rwsem);
    if (subs->stream->chip->shutdown) {
    ret = -ENODEV;
    goto unlock;
    @@ -582,7 +582,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
    ret = start_endpoints(subs, 1);

    unlock:
    - mutex_unlock(&subs->stream->chip->shutdown_mutex);
    + up_read(&subs->stream->chip->shutdown_rwsem);
    return ret;
    }

    diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
    index b8233eb..ef42797 100644
    --- a/sound/usb/usbaudio.h
    +++ b/sound/usb/usbaudio.h
    @@ -37,7 +37,7 @@ struct snd_usb_audio {
    struct usb_interface *pm_intf;
    u32 usb_id;
    struct mutex mutex;
    - struct mutex shutdown_mutex;
    + struct rw_semaphore shutdown_rwsem;
    unsigned int shutdown:1;
    unsigned int probing:1;
    unsigned int autosuspended:1;
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2012-12-13 15:21    [W:4.079 / U:0.064 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site