The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. Possible dependencies: f3c23bea598a ("drm/amd/display: Uninitialized variables causing 4k60 UCLK to stay at DPM1 and not DPM0") 6d4727c80947 ("drm/amd/display: Add check for DET fetch latency hiding for dcn32") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f3c23bea598ab7e8e4b8c5ca66598921310f718e Mon Sep 17 00:00:00 2001 From: Samson Tam <samson.tam@xxxxxxx> Date: Mon, 5 Dec 2022 11:08:40 -0500 Subject: [PATCH] drm/amd/display: Uninitialized variables causing 4k60 UCLK to stay at DPM1 and not DPM0 [Why] SwathSizePerSurfaceY[] and SwathSizePerSurfaceC[] values are uninitialized because we are using += instead of = operator. [How] Assign values in loop with = operator. Acked-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Signed-off-by: Samson Tam <samson.tam@xxxxxxx> Reviewed-by: Aric Cyr <aric.cyr@xxxxxxx> Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # 6.0.x, 6.1.x diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c index 5af601cff1a0..b53feeaf5cf1 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c @@ -6257,12 +6257,12 @@ bool dml32_CalculateDETSwathFillLatencyHiding(unsigned int NumberOfActiveSurface double SwathSizePerSurfaceC[DC__NUM_DPP__MAX]; bool NotEnoughDETSwathFillLatencyHiding = false; - /* calculate sum of single swath size for all pipes in bytes*/ + /* calculate sum of single swath size for all pipes in bytes */ for (k = 0; k < NumberOfActiveSurfaces; k++) { - SwathSizePerSurfaceY[k] += SwathHeightY[k] * SwathWidthY[k] * BytePerPixelInDETY[k] * NumOfDPP[k]; + SwathSizePerSurfaceY[k] = SwathHeightY[k] * SwathWidthY[k] * BytePerPixelInDETY[k] * NumOfDPP[k]; if (SwathHeightC[k] != 0) - SwathSizePerSurfaceC[k] += SwathHeightC[k] * SwathWidthC[k] * BytePerPixelInDETC[k] * NumOfDPP[k]; + SwathSizePerSurfaceC[k] = SwathHeightC[k] * SwathWidthC[k] * BytePerPixelInDETC[k] * NumOfDPP[k]; else SwathSizePerSurfaceC[k] = 0;