From: Hui Wang <hui.w...@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.w...@canonical.com> Cc: <sta...@vger.kernel.org> Link: https://lore.kernel.org/r/20200930055146.5665-1-hui.w...@canonical.com Signed-off-by: Takashi Iwai <ti...@suse.de> Signed-off-by: Greg Kroah-Hartman <gre...@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);
