[PATCH v2] backlight: mp3309c: fix uninitialized local variable

From: Flavio Suligoi
Date: Wed Nov 29 2023 - 11:45:27 EST


In the function "pm3309c_parse_dt_node", when the dimming analog control
mode (by I2C messages) is enabled, the local variable "prop_levels" is
tested without any initialization, as indicated by the following smatch
warning:

drivers/video/backlight/mp3309c.c:279 pm3309c_parse_dt_node() error: uninitialized symbol 'prop_levels'.

To avoid any problem in case of undefined behavior, we need to initialize
it to "NULL".

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/dri-devel/af0a1870-693b-442f-9b11-0503cfcd944a@moroto.mountain/
Fixes: 2e914516a58c ("backlight: mp3309c: Add support for MPS MP3309C")
Signed-off-by: Flavio Suligoi <f.suligoi@xxxxxxx>
---

v2:
- remove redundant initialization of "prop_pwms" variable
- remove "thanks to Dan Carpenter for the report"
- add "Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>" tag
- add "Closes:" tag

drivers/video/backlight/mp3309c.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index 3fe4469ef43f..34d71259fac1 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -203,7 +203,8 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
struct mp3309c_platform_data *pdata)
{
struct device_node *node = chip->dev->of_node;
- struct property *prop_pwms, *prop_levels;
+ struct property *prop_pwms;
+ struct property *prop_levels = NULL;
int length = 0;
int ret, i;
unsigned int num_levels, tmp_value;
--
2.34.1