[PATCH] drm: msm: Check cmd_db_read_aux_data() for failure

From: Stephen Boyd
Date: Thu Nov 29 2018 - 11:38:31 EST

We need to check the call to cmd_db_read_aux_data() for the error case,
so that we don't continue and use potentially uninitialized values for
'pri_count' and 'sec_count'. Otherwise, we get the following compiler

drivers/gpu/drm/msm/adreno/a6xx_gmu.c: In function 'a6xx_gmu_rpmh_arc_votes_init.isra.12':
drivers/gpu/drm/msm/adreno/a6xx_gmu.c:943:12: warning: 'pri_count' is used uninitialized in this function [-Wuninitialized]
pri_count >>= 1;
drivers/gpu/drm/msm/adreno/a6xx_gmu.c:948:12: warning: 'sec_count' may be used uninitialized in this function
sec_count >>= 1;

Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Cc: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Evan Green <evgreen@xxxxxxxxxxxx>
Cc: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Fixes: ed3cafa79ea7 ("soc: qcom: cmd-db: Stop memcpy()ing in cmd_db_read_aux_data()")
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 8cd294e2846d..b450f7ea0422 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -936,6 +936,8 @@ static int a6xx_gmu_rpmh_arc_votes_init(struct device *dev, u32 *votes,
size_t pri_count, sec_count;

pri = cmd_db_read_aux_data(id, &pri_count);
+ if (IS_ERR(pri))
+ return PTR_ERR(pri);
* The data comes back as an array of unsigned shorts so adjust the
* count accordingly
@@ -945,6 +947,9 @@ static int a6xx_gmu_rpmh_arc_votes_init(struct device *dev, u32 *votes,
return -EINVAL;

sec = cmd_db_read_aux_data("mx.lvl", &sec_count);
+ if (IS_ERR(sec))
+ return PTR_ERR(sec);
sec_count >>= 1;
if (!sec_count)
return -EINVAL;
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