From: Josip Pavic <josip.pavic@amd.com>
Date: Tue, 5 Dec 2023 21:57:27 +0000 (-0500)
Subject: drm/amd/display: dereference variable before checking for zero
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3582e0ba8a675d72c3cc6dd1b847e6aa757845da;p=linux.git

drm/amd/display: dereference variable before checking for zero

[Why]
Driver incorrectly checks if pointer variable OutBpp is null instead of
if the value being pointed to is zero.

[How]
Dereference OutBpp before checking for a value of zero.

Reviewed-by: Chaitanya Dhere <chaitanya.dhere@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Josip Pavic <josip.pavic@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c
index 180f8a98a361a..b95bf27f2fe2f 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c
@@ -5420,7 +5420,7 @@ static void CalculateOutputLink(
 					*OutBpp = TruncToValidBPP((1 - Downspreading / 100) * 13500, OutputLinkDPLanes, HTotal, HActive, PixelClockBackEnd, ForcedOutputLinkBPP, LinkDSCEnable, Output,
 												OutputFormat, DSCInputBitPerComponent, NumberOfDSCSlices, (dml_uint_t)AudioSampleRate, AudioSampleLayout, ODMModeNoDSC, ODMModeDSC, RequiredSlots);
 
-					if (OutBpp == 0 && PHYCLKD32PerState < 20000 / 32 && DSCEnable == dml_dsc_enable_if_necessary && ForcedOutputLinkBPP == 0) {
+					if (*OutBpp == 0 && PHYCLKD32PerState < 20000 / 32 && DSCEnable == dml_dsc_enable_if_necessary && ForcedOutputLinkBPP == 0) {
 						*RequiresDSC = true;
 						LinkDSCEnable = true;
 						*OutBpp = TruncToValidBPP((1 - Downspreading / 100) * 13500, OutputLinkDPLanes, HTotal, HActive, PixelClockBackEnd, ForcedOutputLinkBPP, LinkDSCEnable, Output,