lkml.org 
[lkml]   [2020]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.8 055/633] ALSA: hda - Dont register a cb func if it is registered already
    Date
    From: Hui Wang <hui.wang@canonical.com>

    commit f4794c6064a83d2c57b264bd299c367d172d1044 upstream.

    If the caller of enable_callback_mst() passes a cb func, the callee
    function will malloc memory and link this cb func to the list
    unconditionally. This will introduce problem if caller is in the
    hda_codec_ops.init() since the init() will be repeatedly called in the
    codec rt_resume().

    So far, the patch_hdmi.c and patch_ca0132.c call enable_callback_mst()
    in the hda_codec_ops.init().

    Signed-off-by: Hui Wang <hui.wang@canonical.com>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20200930055146.5665-1-hui.wang@canonical.com
    Signed-off-by: Takashi Iwai <tiwai@suse.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    sound/pci/hda/hda_jack.c | 14 +++++++++++++-
    1 file changed, 13 insertions(+), 1 deletion(-)

    --- a/sound/pci/hda/hda_jack.c
    +++ b/sound/pci/hda/hda_jack.c
    @@ -275,6 +275,18 @@ int snd_hda_jack_detect_state_mst(struct
    }
    EXPORT_SYMBOL_GPL(snd_hda_jack_detect_state_mst);

    +static bool func_is_already_in_callback_list(struct hda_jack_tbl *jack,
    + hda_jack_callback_fn func)
    +{
    + struct hda_jack_callback *cb;
    +
    + for (cb = jack->callback; cb; cb = cb->next) {
    + if (cb->func == func)
    + return true;
    + }
    + return false;
    +}
    +
    /**
    * snd_hda_jack_detect_enable_mst - enable the jack-detection
    * @codec: the HDA codec
    @@ -297,7 +309,7 @@ snd_hda_jack_detect_enable_callback_mst(
    jack = snd_hda_jack_tbl_new(codec, nid, dev_id);
    if (!jack)
    return ERR_PTR(-ENOMEM);
    - if (func) {
    + if (func && !func_is_already_in_callback_list(jack, func)) {
    callback = kzalloc(sizeof(*callback), GFP_KERNEL);
    if (!callback)
    return ERR_PTR(-ENOMEM);

    \
     
     \ /
      Last update: 2020-10-27 18:24    [W:4.043 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site