drm/i915/selftests: fix uninitialized variable sum when summing up values

Currently the variable sum is not uninitialized and hence will cause an
incorrect result in the summation values.  Fix this by initializing
sum to the first item in the summation.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 3c7a44bbbfa7 ("drm/i915/selftests: Perform some basic cycle counting of MI ops")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191210143205.338308-1-colin.king@canonical.com

diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
index 761d81f4bd68036938e8c60fe997cef1ebdd1ac3..f88e445a1cae84358cd16de76579fb910e4ded26 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
@@ -108,7 +108,7 @@ static u32 trifilter(u32 *a)
 
        sort(a, COUNT, sizeof(*a), cmp_u32, NULL);
 
-       sum += mul_u32_u32(a[2], 2);
+       sum = mul_u32_u32(a[2], 2);
        sum += a[1];
        sum += a[3];