[PATCH 4/7] drm/amd/powerplay: Zero initialize freq in smu_v11_0_get_current_clk_freq

From: Nathan Chancellor
Date: Thu Jul 04 2019 - 01:52:59 EST


clang warns (trimmed for brevity):

drivers/gpu/drm/amd/amdgpu/../powerplay/smu_v11_0.c:1098:10: warning:
variable 'freq' is used uninitialized whenever '?:' condition is false
[-Wsometimes-uninitialized]
ret = smu_get_current_clk_freq_by_table(smu, clk_id, &freq);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If get_current_clk_freq_by_table is ever NULL, freq will fail to be
properly initialized. Zero initialize it to avoid using uninitialized
stack values.

smu_get_current_clk_freq_by_table expands to a ternary operator
conditional on smu->funcs->get_current_clk_freq_by_table being not NULL.
When this is false, freq will be uninitialized. Zero initialize freq to
avoid using random stack values if that ever happens.

Fixes: e36182490dec ("drm/amd/powerplay: fix dpm freq unit error (10KHz -> Mhz)")
Link: https://github.com/ClangBuiltLinux/linux/issues/585
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
drivers/gpu/drm/amd/powerplay/smu_v11_0.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
index 632a20587c8b..a6f8cd6df7f1 100644
--- a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
+++ b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
@@ -1088,7 +1088,7 @@ static int smu_v11_0_get_current_clk_freq(struct smu_context *smu,
uint32_t *value)
{
int ret = 0;
- uint32_t freq;
+ uint32_t freq = 0;

if (clk_id >= SMU_CLK_COUNT || !value)
return -EINVAL;
--
2.22.0