ALSA: hda - Don't register a cb func if it is registered already (f4794c60) · Commits · 戴 / test

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>

sound/pci/hda/hda_jack.c

+13 −1

Original line number	Diff line number	Diff line
		@@ -275,6 +275,18 @@ 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)
		{
		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(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) {
		if (func && !func_is_already_in_callback_list(jack, func)) {
		callback = kzalloc(sizeof(*callback), GFP_KERNEL);
		if (!callback)
		return ERR_PTR(-ENOMEM);

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