[PATCH] media: rzg2l-cru: Remove unnecessary shadowing of ret in rzg2l_csi2_s_stream()

[PATCH] media: rzg2l-cru: Remove unnecessary shadowing of ret in rzg2l_csi2_s_stream()

[Nathan Chancellor]

Clang warns:

  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:445:7: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                  if (ret)
                      ^~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:475:9: note: uninitialized use occurs here
          return ret;
                ^~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:445:3: note: remove the 'if' if its condition is always false
                  if (ret)
                  ^~~~~~~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:441:7: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                  if (ret)
                      ^~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:475:9: note: uninitialized use occurs here
          return ret;
                ^~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:441:3: note: remove the 'if' if its condition is always false
                  if (ret)
                  ^~~~~~~~
  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:431:9: note: initialize the variable 'ret' to silence this warning
          int ret;
                ^
                  = 0
  2 errors generated.

ret is unnecessarily shadowed, meaning the assignments to ret within the
first 'if (enable)' block are only applied to the inner scope, not the
outer one as intended. Remove the shadowing to fix the warnings and make
everything work correctly.

Fixes: 51e8415e39a9 ("media: platform: Add Renesas RZ/G2L MIPI CSI-2 receiver driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1764
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
index aa752b80574c..3deb09be6400 100644
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
@@ -431,8 +431,6 @@ static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
 	int ret;
 
 	if (enable) {
-		int ret;
-
 		ret = pm_runtime_resume_and_get(csi2->dev);
 		if (ret)
 			return ret;

base-commit: 6a5a4514854a637d01c50f5ea17b28f78b31ddb8
-- 
2.38.1

RE: [PATCH] media: rzg2l-cru: Remove unnecessary shadowing of ret in rzg2l_csi2_s_stream()

[Prabhakar Mahadev Lad]

Hi Nathan,

Thank you for the patch.

> -----Original Message-----
> From: Nathan Chancellor <nathan@kernel.org>
> Sent: 28 November 2022 06:16
> To: Mauro Carvalho Chehab <mchehab@kernel.org>; Sakari Ailus <sakari.ailus@linux.intel.com>; Prabhakar
> Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Cc: Nick Desaulniers <ndesaulniers@google.com>; Tom Rix <trix@redhat.com>; linux-
> media@vger.kernel.org; linux-kernel@vger.kernel.org; llvm@lists.linux.dev; patches@lists.linux.dev;
> Nathan Chancellor <nathan@kernel.org>
> Subject: [PATCH] media: rzg2l-cru: Remove unnecessary shadowing of ret in rzg2l_csi2_s_stream()
> 
> Clang warns:
> 
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:445:7: error: variable 'ret' is used
> uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>                   if (ret)
>                       ^~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:475:9: note: uninitialized use occurs here
>           return ret;
>                 ^~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:445:3: note: remove the 'if' if its condition
> is always false
>                   if (ret)
>                   ^~~~~~~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:441:7: error: variable 'ret' is used
> uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>                   if (ret)
>                       ^~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:475:9: note: uninitialized use occurs here
>           return ret;
>                 ^~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:441:3: note: remove the 'if' if its condition
> is always false
>                   if (ret)
>                   ^~~~~~~~
>   drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c:431:9: note: initialize the variable 'ret' to
> silence this warning
>           int ret;
>                 ^
>                   = 0
>   2 errors generated.
> 
> ret is unnecessarily shadowed, meaning the assignments to ret within the first 'if (enable)' block are
> only applied to the inner scope, not the outer one as intended. Remove the shadowing to fix the
> warnings and make everything work correctly.
> 
> Fixes: 51e8415e39a9 ("media: platform: Add Renesas RZ/G2L MIPI CSI-2 receiver driver")
> Link:
> https://jpn01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2FClangBuiltLinux%2Flinux
> %2Fissues%2F1764&amp;data=05%7C01%7Cprabhakar.mahadev-
> lad.rj%40bp.renesas.com%7C76d2a49f939a46e8d15208dad1081ed7%7C53d82571da1947e49cb4625a166a4a2a%7C0%7C0%
> 7C638052130064697087%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXV
> CI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=fp%2F1JCtgKY8E6qVMRlLewVLYc9WDZ%2ByNtg6t%2BGqIUvk%3D&amp;reserved=
> 0
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c | 2 --
>  1 file changed, 2 deletions(-)
> 
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Cheers,
Prabhakar