diff mbox series

[v2] ASoC: codes: src4xxx: Avoid clang -Wsometimes-uninitialized in src4xxx_hw_params()

Message ID 20220823151939.2493697-1-nathan@kernel.org
State Accepted
Commit 7d3ac70d82080f7a934402d66c5238e1d99be412
Headers show
Series [v2] ASoC: codes: src4xxx: Avoid clang -Wsometimes-uninitialized in src4xxx_hw_params() | expand

Commit Message

Nathan Chancellor Aug. 23, 2022, 3:19 p.m. UTC 
Clang warns:

  sound/soc/codecs/src4xxx.c:280:3: error: variable 'd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
                  default:
                  ^~~~~~~
  sound/soc/codecs/src4xxx.c:298:59: note: uninitialized use occurs here
                  ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_11, d);
                                                                          ^
  sound/soc/codecs/src4xxx.c:223:20: note: initialize the variable 'd' to silence this warning
          int val, pj, jd, d;
                            ^
                            = 0
  sound/soc/codecs/src4xxx.c:280:3: error: variable 'jd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
                  default:
                  ^~~~~~~
  sound/soc/codecs/src4xxx.c:293:59: note: uninitialized use occurs here
                  ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_10, jd);
                                                                          ^~
  sound/soc/codecs/src4xxx.c:223:17: note: initialize the variable 'jd' to silence this warning
          int val, pj, jd, d;
                        ^
                          = 0
  sound/soc/codecs/src4xxx.c:280:3: error: variable 'pj' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
                  default:
                  ^~~~~~~
  sound/soc/codecs/src4xxx.c:288:59: note: uninitialized use occurs here
                  ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_0F, pj);
                                                                          ^~
  sound/soc/codecs/src4xxx.c:223:13: note: initialize the variable 'pj' to silence this warning
          int val, pj, jd, d;
                    ^
                      = 0
  3 errors generated.

The datasheet does not have any default values for these regmap values
so pick some arbitrary values and print to the user that this is the
case to silence the warnings.

Link: https://github.com/ClangBuiltLinux/linux/issues/1691
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: "Sudip Mukherjee (Codethink)" <sudipm.mukherjee@gmail.com>
Suggested-by: Matt Flax <flatmax@flatmax.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---

v1 -> v2: https://lore.kernel.org/20220822183101.1115095-1-nathan@kernel.org/

* Don't return early, just initialize the values to some arbitrary
  numbers and try to hobble along, as other parts of the chip may be
  functional.

* Add message and comment to describe this situation.

 sound/soc/codecs/src4xxx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)


base-commit: 94f072748337424c9cf92cd018532a34db3a5516

Comments

Matt Flax Aug. 23, 2022, 9:32 p.m. UTC | #1 
This patch looks good.

On 24/8/22 01:19, Nathan Chancellor wrote:
> Clang warns:
>
>    sound/soc/codecs/src4xxx.c:280:3: error: variable 'd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                    default:
>                    ^~~~~~~
>    sound/soc/codecs/src4xxx.c:298:59: note: uninitialized use occurs here
>                    ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_11, d);
>                                                                            ^
>    sound/soc/codecs/src4xxx.c:223:20: note: initialize the variable 'd' to silence this warning
>            int val, pj, jd, d;
>                              ^
>                              = 0
>    sound/soc/codecs/src4xxx.c:280:3: error: variable 'jd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                    default:
>                    ^~~~~~~
>    sound/soc/codecs/src4xxx.c:293:59: note: uninitialized use occurs here
>                    ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_10, jd);
>                                                                            ^~
>    sound/soc/codecs/src4xxx.c:223:17: note: initialize the variable 'jd' to silence this warning
>            int val, pj, jd, d;
>                          ^
>                            = 0
>    sound/soc/codecs/src4xxx.c:280:3: error: variable 'pj' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                    default:
>                    ^~~~~~~
>    sound/soc/codecs/src4xxx.c:288:59: note: uninitialized use occurs here
>                    ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_0F, pj);
>                                                                            ^~
>    sound/soc/codecs/src4xxx.c:223:13: note: initialize the variable 'pj' to silence this warning
>            int val, pj, jd, d;
>                      ^
>                        = 0
>    3 errors generated.
>
> The datasheet does not have any default values for these regmap values
> so pick some arbitrary values and print to the user that this is the
> case to silence the warnings.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1691
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: "Sudip Mukherjee (Codethink)" <sudipm.mukherjee@gmail.com>
> Suggested-by: Matt Flax <flatmax@flatmax.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>
> v1 -> v2: https://lore.kernel.org/20220822183101.1115095-1-nathan@kernel.org/
>
> * Don't return early, just initialize the values to some arbitrary
>    numbers and try to hobble along, as other parts of the chip may be
>    functional.
>
> * Add message and comment to describe this situation.
>
>   sound/soc/codecs/src4xxx.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/sound/soc/codecs/src4xxx.c b/sound/soc/codecs/src4xxx.c
> index a8f143057b41..db4e280dd055 100644
> --- a/sound/soc/codecs/src4xxx.c
> +++ b/sound/soc/codecs/src4xxx.c
> @@ -280,9 +280,14 @@ static int src4xxx_hw_params(struct snd_pcm_substream *substream,
>   		default:
>   			/* don't error out here,
>   			 * other parts of the chip are still functional
> +			 * Dummy initialize variables to avoid
> +			 * -Wsometimes-uninitialized from clang.
>   			 */
>   			dev_info(component->dev,
> -				"Couldn't set the RCV PLL as this master clock rate is unknown\n");
> +				"Couldn't set the RCV PLL as this master clock rate is unknown. Chosen regmap values may not match real world values.\n");
> +			pj = 0x0;
> +			jd = 0xff;
> +			d = 0xff;
>   			break;
>   		}
>   		ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_0F, pj);
>
> base-commit: 94f072748337424c9cf92cd018532a34db3a5516
Mark Brown Aug. 24, 2022, 11:12 a.m. UTC | #2 
On Tue, 23 Aug 2022 08:19:40 -0700, Nathan Chancellor wrote:
> Clang warns:
> 
>   sound/soc/codecs/src4xxx.c:280:3: error: variable 'd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                   default:
>                   ^~~~~~~
>   sound/soc/codecs/src4xxx.c:298:59: note: uninitialized use occurs here
>                   ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_11, d);
>                                                                           ^
>   sound/soc/codecs/src4xxx.c:223:20: note: initialize the variable 'd' to silence this warning
>           int val, pj, jd, d;
>                             ^
>                             = 0
>   sound/soc/codecs/src4xxx.c:280:3: error: variable 'jd' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                   default:
>                   ^~~~~~~
>   sound/soc/codecs/src4xxx.c:293:59: note: uninitialized use occurs here
>                   ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_10, jd);
>                                                                           ^~
>   sound/soc/codecs/src4xxx.c:223:17: note: initialize the variable 'jd' to silence this warning
>           int val, pj, jd, d;
>                         ^
>                           = 0
>   sound/soc/codecs/src4xxx.c:280:3: error: variable 'pj' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
>                   default:
>                   ^~~~~~~
>   sound/soc/codecs/src4xxx.c:288:59: note: uninitialized use occurs here
>                   ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_0F, pj);
>                                                                           ^~
>   sound/soc/codecs/src4xxx.c:223:13: note: initialize the variable 'pj' to silence this warning
>           int val, pj, jd, d;
>                     ^
>                       = 0
>   3 errors generated.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: codes: src4xxx: Avoid clang -Wsometimes-uninitialized in src4xxx_hw_params()
      commit: 7d3ac70d82080f7a934402d66c5238e1d99be412

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark
diff mbox series

Patch

diff --git a/sound/soc/codecs/src4xxx.c b/sound/soc/codecs/src4xxx.c
index a8f143057b41..db4e280dd055 100644
--- a/sound/soc/codecs/src4xxx.c
+++ b/sound/soc/codecs/src4xxx.c
@@ -280,9 +280,14 @@  static int src4xxx_hw_params(struct snd_pcm_substream *substream,
 		default:
 			/* don't error out here,
 			 * other parts of the chip are still functional
+			 * Dummy initialize variables to avoid
+			 * -Wsometimes-uninitialized from clang.
 			 */
 			dev_info(component->dev,
-				"Couldn't set the RCV PLL as this master clock rate is unknown\n");
+				"Couldn't set the RCV PLL as this master clock rate is unknown. Chosen regmap values may not match real world values.\n");
+			pj = 0x0;
+			jd = 0xff;
+			d = 0xff;
 			break;
 		}
 		ret = regmap_write(src4xxx->regmap, SRC4XXX_RCV_PLL_0F, pj);