If the cb function is already registered, should return the pointer of the structure hda_jack_callback which contains this cb func, but instead it returns the NULL.

Now fix it by replacing func_is_already_in_callback_list() with find_callback_from_list().

Fixes: f4794c6064a8 ("ALSA:hda - Don't register a cb func if it is registered already") Reported-and-suggested-by: Dan Carpenter dan.carpenter@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Hui Wang hui.wang@canonical.com --- sound/pci/hda/hda_jack.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/sound/pci/hda/hda_jack.c b/sound/pci/hda/hda_jack.c index ded4813f8b54..588059428d8f 100644 --- a/sound/pci/hda/hda_jack.c +++ b/sound/pci/hda/hda_jack.c @@ -275,16 +275,21 @@ int snd_hda_jack_detect_state_mst(struct hda_codec *codec, } 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) +static struct hda_jack_callback * +find_callback_from_list(struct hda_jack_tbl *jack, + hda_jack_callback_fn func) { struct hda_jack_callback *cb;

+ if (!func) + return NULL; + for (cb = jack->callback; cb; cb = cb->next) { if (cb->func == func) - return true; + return cb; } - return false; + + return NULL; }

/** @@ -309,7 +314,10 @@ snd_hda_jack_detect_enable_callback_mst(struct hda_codec *codec, hda_nid_t nid, jack = snd_hda_jack_tbl_new(codec, nid, dev_id); if (!jack) return ERR_PTR(-ENOMEM); - if (func && !func_is_already_in_callback_list(jack, func)) { + + callback = find_callback_from_list(jack, func); + + if (func && !callback) { callback = kzalloc(sizeof(*callback), GFP_KERNEL); if (!callback) return ERR_PTR(-ENOMEM);