From 033e4040d453f1f7111e5957a54f3019eb089cc6 Mon Sep 17 00:00:00 2001

From: Hui Wang <hui.wang@canonical.com>

Date: Thu, 22 Oct 2020 11:02:21 +0800

Subject: [PATCH] ALSA: hda - Fix the return value if cb func is already registered

Git-commit: 033e4040d453f1f7111e5957a54f3019eb089cc6

Patch-mainline: v5.10-rc1

References: git-fixes

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>

Link: https://lore.kernel.org/r/20201022030221.22393-1-hui.wang@canonical.com

Signed-off-by: Takashi Iwai <tiwai@suse.de>

---

 sound/pci/hda/hda_jack.c |   18 +++++++++++++-----

 1 file changed, 13 insertions(+), 5 deletions(-)

--- a/sound/pci/hda/hda_jack.c

+++ b/sound/pci/hda/hda_jack.c

@@ -235,16 +235,21 @@ int snd_hda_jack_detect_state(struct hda

 }

 EXPORT_SYMBOL_GPL(snd_hda_jack_detect_state);

-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;

 }

 /**

@@ -268,7 +273,10 @@ snd_hda_jack_detect_enable_callback(stru

 	jack = snd_hda_jack_tbl_new(codec, nid);

 	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);