There are a handful of bit-wise or'ing of values into the uninitialized
variable ret resulting in garbage results. Fix this by ininitializing
ret to zero.

Fixes: bbca8e7050e0 ("ASoC: rt-sdw-common: Common functions for Realtek soundwire driver")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
---
 sound/soc/codecs/rt-sdw-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/rt-sdw-common.c b/sound/soc/codecs/rt-sdw-common.c
index 9ed0e9855699..a422da6cf702 100644
--- a/sound/soc/codecs/rt-sdw-common.c
+++ b/sound/soc/codecs/rt-sdw-common.c
@@ -101,21 +101,21 @@ EXPORT_SYMBOL_GPL(rt_sdca_index_update_bits);
  * rt_sdca_btn_type - Decision of button type.
  *
  * @buffer: UMP message buffer.
  *
  * A button type will be returned regarding to buffer,
  * it returns zero if buffer cannot be recognized.
  */
 int rt_sdca_btn_type(unsigned char *buffer)
 {
 	u8 btn_type = 0;
-	int ret;
+	int ret = 0;
 
 	btn_type |= buffer[0] & 0xf;
 	btn_type |= (buffer[0] >> 4) & 0xf;
 	btn_type |= buffer[1] & 0xf;
 	btn_type |= (buffer[1] >> 4) & 0xf;
 
 	if (btn_type & BIT(0))
 		ret |= SND_JACK_BTN_2;
 	if (btn_type & BIT(1))
 		ret |= SND_JACK_BTN_3;
-- 
2.39.5

On Tue, Oct 08, 2024 at 05:47:07PM +0100, Colin Ian King wrote:
> There are a handful of bit-wise or'ing of values into the uninitialized
> variable ret resulting in garbage results. Fix this by ininitializing
> ret to zero.

I'm very disappinted in the compiler for not noticing this :(

On Tue, Oct 08, 2024 at 06:04:08PM +0100, Mark Brown wrote:
> On Tue, Oct 08, 2024 at 05:47:07PM +0100, Colin Ian King wrote:
> > There are a handful of bit-wise or'ing of values into the uninitialized
> > variable ret resulting in garbage results. Fix this by ininitializing
> > ret to zero.
> 
> I'm very disappinted in the compiler for not noticing this :(

We disabled GCC's uninitialized variable check years ago before we enabled
-Werror.  Clang does catch this.

  CC      sound/soc/codecs/rt-sdw-common.o
sound/soc/codecs/rt-sdw-common.c:119:3: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
                ret |= SND_JACK_BTN_2;
                ^~~
sound/soc/codecs/rt-sdw-common.c:111:9: note: initialize the variable 'ret' to silence this warning
        int ret;
               ^
                = 0

regards,
dan carpenter

> -----Original Message-----
> From: Mark Brown <broonie@kernel.org>
> Sent: Wednesday, October 9, 2024 1:04 AM
> To: Colin Ian King <colin.i.king@gmail.com>
> Cc: Oder Chiou <oder_chiou@realtek.com>; Liam Girdwood
> <lgirdwood@gmail.com>; Jaroslav Kysela <perex@perex.cz>; Takashi Iwai
> <tiwai@suse.com>; Jack Yu <jack.yu@realtek.com>;
> linux-sound@vger.kernel.org; kernel-janitors@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH][next] ASoC: rt-sdw-common: Fix bit-wise or'ing of values
> into uninitialized variable ret
> 
> On Tue, Oct 08, 2024 at 05:47:07PM +0100, Colin Ian King wrote:
> > There are a handful of bit-wise or'ing of values into the
> > uninitialized variable ret resulting in garbage results. Fix this by
> > ininitializing ret to zero.
> 
> I'm very disappinted in the compiler for not noticing this :(

I'm sorry for such mistake. I've sent a patch to fix this yesterday, please refer attachment.
Fix issue of warning messages caused by some variables.

Signed-off-by: Jack Yu <jack.yu@realtek.com>
---
 sound/soc/codecs/rt-sdw-common.c | 2 +-
 sound/soc/codecs/rt721-sdca.c    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/rt-sdw-common.c b/sound/soc/codecs/rt-sdw-common.c
index 9ed0e9855699..a422da6cf702 100644
--- a/sound/soc/codecs/rt-sdw-common.c
+++ b/sound/soc/codecs/rt-sdw-common.c
@@ -108,7 +108,7 @@ EXPORT_SYMBOL_GPL(rt_sdca_index_update_bits);
 int rt_sdca_btn_type(unsigned char *buffer)
 {
 	u8 btn_type = 0;
-	int ret;
+	int ret = 0;
 
 	btn_type |= buffer[0] & 0xf;
 	btn_type |= (buffer[0] >> 4) & 0xf;
diff --git a/sound/soc/codecs/rt721-sdca.c b/sound/soc/codecs/rt721-sdca.c
index 36056cb7a3ca..201cb667c8c1 100644
--- a/sound/soc/codecs/rt721-sdca.c
+++ b/sound/soc/codecs/rt721-sdca.c
@@ -30,7 +30,7 @@ static void rt721_sdca_jack_detect_handler(struct work_struct *work)
 {
 	struct rt721_sdca_priv *rt721 =
 		container_of(work, struct rt721_sdca_priv, jack_detect_work.work);
-	int btn_type = 0, ret;
+	int btn_type = 0;
 
 	if (!rt721->hs_jack)
 		return;
@@ -42,7 +42,7 @@ static void rt721_sdca_jack_detect_handler(struct work_struct *work)
 	if (rt721->scp_sdca_stat1 & SDW_SCP_SDCA_INT_SDCA_6) {
 		rt721->jack_type = rt_sdca_headset_detect(rt721->regmap,
 							RT721_SDCA_ENT_GE49);
-		if (ret < 0)
+		if (rt721->jack_type < 0)
 			return;
 	}
 
-- 
2.34.1