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From:   Nathan Chancellor <nathan@kernel.org>
To:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Kevin Wang <kevin1.wang@amd.com>,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
        Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH] drm/amd/pm/swsmu: Avoid using structure_size uninitialized in smu_cmn_init_soft_gpu_metrics
Date:   Thu, 18 Feb 2021 15:48:50 -0700
Message-Id: <20210218224849.5591-1-nathan@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Clang warns:

drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:764:2: warning:
variable 'structure_size' is used uninitialized whenever switch default
is taken [-Wsometimes-uninitialized]
        default:
        ^~~~~~~
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:770:23: note:
uninitialized use occurs here
        memset(header, 0xFF, structure_size);
                             ^~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:753:25: note:
initialize the variable 'structure_size' to silence this warning
        uint16_t structure_size;
                               ^
                                = 0
1 warning generated.

Return in the default case, as the size of the header will not be known.

Fixes: de4b7cd8cb87 ("drm/amd/pm/swsmu: unify the init soft gpu metrics function")
Link: https://github.com/ClangBuiltLinux/linux/issues/1304
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
index bb620fdd4cd2..bcedd4d92e35 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
@@ -762,7 +762,7 @@ void smu_cmn_init_soft_gpu_metrics(void *table, uint8_t frev, uint8_t crev)
 		structure_size = sizeof(struct gpu_metrics_v2_0);
 		break;
 	default:
-		break;
+		return;
 	}
 
 #undef METRICS_VERSION
-- 
2.30.1