drm/amd/display: fix use of uninitialized memory

BugLink: https://bugs.launchpad.net/bugs/1836287
[ Upstream commit f3e077d95ca0a016fdf3d6b1e97a9910dfdaff17 ]

DML does not calculate chroma values for RQ when surface is not YUV, but DC
will unconditionally use the uninitialized values for HW programming.
This does not cause visual corruption since HW will ignore garbage chroma
values when surface is not YUV, but causes presubmission tests to fail
golden value comparison.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Signed-off-by: Eryk Brol <eryk.brol@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
index 1e4b1e38340123708b9b009f6b3d580eb3e2bb8e..4eb9210bf6756c6a51f1a712a1492f3a2a26783e 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c
@@ -230,6 +230,8 @@ void dml1_extract_rq_regs(
        extract_rq_sizing_regs(mode_lib, &(rq_regs->rq_regs_l), rq_param.sizing.rq_l);
        if (rq_param.yuv420)
                extract_rq_sizing_regs(mode_lib, &(rq_regs->rq_regs_c), rq_param.sizing.rq_c);
+       else
+               memset(&(rq_regs->rq_regs_c), 0, sizeof(rq_regs->rq_regs_c));
 
        rq_regs->rq_regs_l.swath_height = dml_log2(rq_param.dlg.rq_l.swath_height);
        rq_regs->rq_regs_c.swath_height = dml_log2(rq_param.dlg.rq_c.swath_height);