[PATCH] ASoC: aw88395: Fix kernel panic caused by invalid GPIO error pointer

[PATCH] ASoC: aw88395: Fix kernel panic caused by invalid GPIO error pointer

[wangdich9700]

From: wangdicheng <wangdicheng@kylinos.cn>

In aw88395_i2c_probe(), if `devm_gpiod_get_optional()` fails, it returns
an ERR_PTR() error pointer. The current code only prints a message and
continues execution, leaving `aw88395->reset_gpio` as an invalid pointer.

Later, in `aw88395_hw_reset()`, this invalid pointer is passed to
`gpiod_set_value_cansleep()`, which dereferences it and causes a kernel
panic.

For optional GPIOs, `devm_gpiod_get_optional()` returns NULL if the GPIO
is not defined in the DT, which is safe. If it returns an ERR_PTR, it
means a real error occurred (e.g., -EPROBE_DEFER) and the probe must be
aborted. Fix this by returning the error code when IS_ERR() is true.

Signed-off-by: wangdicheng <wangdicheng@kylinos.cn>
---
 sound/soc/codecs/aw88395/aw88395.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/aw88395/aw88395.c b/sound/soc/codecs/aw88395/aw88395.c
index 3602b5b9f7d7..e60cd7e239cc 100644
--- a/sound/soc/codecs/aw88395/aw88395.c
+++ b/sound/soc/codecs/aw88395/aw88395.c
@@ -523,7 +523,7 @@ static int aw88395_i2c_probe(struct i2c_client *i2c)
 
 	aw88395->reset_gpio = devm_gpiod_get_optional(&i2c->dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(aw88395->reset_gpio))
-		dev_info(&i2c->dev, "reset gpio not defined\n");
+		return PTR_ERR(aw88395->reset_gpio);
 
 	/* hardware reset */
 	aw88395_hw_reset(aw88395);
-- 
2.25.1

Re: [PATCH] ASoC: aw88395: Fix kernel panic caused by invalid GPIO error pointer

[Mark Brown]

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On Mon, Apr 27, 2026 at 10:29:46AM +0800, wangdich9700@163.com wrote:
> From: wangdicheng <wangdicheng@kylinos.cn>
> 
> In aw88395_i2c_probe(), if `devm_gpiod_get_optional()` fails, it returns
> an ERR_PTR() error pointer. The current code only prints a message and
> continues execution, leaving `aw88395->reset_gpio` as an invalid pointer.
> 
> Later, in `aw88395_hw_reset()`, this invalid pointer is passed to
> `gpiod_set_value_cansleep()`, which dereferences it and causes a kernel
> panic.
> 
> For optional GPIOs, `devm_gpiod_get_optional()` returns NULL if the GPIO
> is not defined in the DT, which is safe. If it returns an ERR_PTR, it
> means a real error occurred (e.g., -EPROBE_DEFER) and the probe must be
> aborted. Fix this by returning the error code when IS_ERR() is true.

This looks OK in so far as it goes but there's other bugs in the driver,
at least printing a dev_err() if the GPIO is missing which doesn't
exactly sound optonal to me.

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