[Intel-gfx] [PATCH] drm: i915: display: intel_dmc: Fixes an unsigned subtraction which can never be negative.

[Harshit Mogalapalli]

smatch warning:
drivers/gpu/drm/i915/display/intel_dmc.c:601 parse_dmc_fw() warn:
unsigned 'fw->size - offset' is never less than zero

Firmware size is size_t and offset is u32. So the subtraction is
unsigned which can never be less than zero.

Fixes: 3d5928a168a9 ("drm/i915/xelpd: Pipe A DMC plugging")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapa...@oracle.com>
---
 drivers/gpu/drm/i915/display/intel_dmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c 
b/drivers/gpu/drm/i915/display/intel_dmc.c
index 0cab18f972d1..2f477c298b00 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
@@ -598,7 +598,7 @@ static void parse_dmc_fw(struct drm_i915_private *dev_priv,
                        continue;
 
                offset = readcount + dmc->dmc_info[id].dmc_offset * 4;
-               if (fw->size - offset < 0) {
+               if (offset > fw->size) {
                        drm_err(&dev_priv->drm, "Reading beyond the fw_size\n");
                        continue;
                }
-- 
2.27.0