openwrt/target/linux/bcm27xx/patches-5.15/950-0675-media-i2c-ov9281-Initialize-id_msb-to-zero-in-ov9281.patch

From 573172b7b51a5b955627bd3d0cde5b2d2c4f9441 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 31 Jan 2022 17:50:43 -0700
Subject: [PATCH] media: i2c: ov9281: Initialize id_msb to zero in
 ov9281_check_sensor_id()

Clang warns:

  drivers/media/i2c/ov9281.c:1132:6: warning: variable 'id_msb' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
          if (!ret)
              ^~~~
  drivers/media/i2c/ov9281.c:1135:9: note: uninitialized use occurs here
          id |= (id_msb << 8);
                 ^~~~~~
  drivers/media/i2c/ov9281.c:1132:2: note: remove the 'if' if its condition is always true
          if (!ret)
          ^~~~~~~~~
  drivers/media/i2c/ov9281.c:1127:20: note: initialize the variable 'id_msb' to silence this warning
          u32 id = 0, id_msb;
                            ^
                             = 0
  1 warning generated.

If the first ov9281_read_reg() call fails, id_msb will be used
uninitialized. However, this warning does not actually matter in
practice because the value of id is not used when either call to
ov9281_read_reg() fails, as the boolean OR will short circuit due to the
ret condition being checked first. Regardless, it is not good to use
variables uninitialized so silence the warning by initializing id_msb to
0, as was done with id.

Fixes: 20855581e0eb ("media: i2c: ov9281: Read chip ID via 2 reads")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/media/i2c/ov9281.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/i2c/ov9281.c
+++ b/drivers/media/i2c/ov9281.c
@@ -1124,7 +1124,7 @@ static int ov9281_check_sensor_id(struct
 				  struct i2c_client *client)
 {
 	struct device *dev = &ov9281->client->dev;
-	u32 id = 0, id_msb;
+	u32 id = 0, id_msb = 0;
 	int ret;
 
 	ret = ov9281_read_reg(client, OV9281_REG_CHIP_ID + 1,