drm/amd/display: Fix hard hang if DSC is disabled

We want to calculate the DTB clock values when DSC is enabled; however,
this is not the current behavior implemented in DCN32. Right now, DML is
trying to calculate DSC values even if DSC is disabled; as a result, we
can have a hard hang due to wrong clock calculation. This commit fixes
this issue by moving the calculation after the DSC check.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 5a701d9df0f75a2ea4897d2a3d51c59e254b1da0..febaff7d7343cb77fc2dd9cc5d34362be2b8edfe 100644 (file)
--- 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
@@ -1686,17 +1686,22 @@ double dml32_RequiredDTBCLK(
                unsigned int              AudioRate,
                unsigned int              AudioLayout)
 {
-       double PixelWordRate = PixelClock /  (OutputFormat == dm_444 ? 1 : 2);
-       double HCActive = dml_ceil(DSCSlices * dml_ceil(OutputBpp *
-                       dml_ceil(HActive / DSCSlices, 1) / 8.0, 1) / 3.0, 1);
-       double HCBlank = 64 + 32 *
-                       dml_ceil(AudioRate *  (AudioLayout == 1 ? 1 : 0.25) * HTotal / (PixelClock * 1000), 1);
-       double AverageTribyteRate = PixelWordRate * (HCActive + HCBlank) / HTotal;
-       double HActiveTribyteRate = PixelWordRate * HCActive / HActive;
+       double PixelWordRate;
+       double HCActive;
+       double HCBlank;
+       double AverageTribyteRate;
+       double HActiveTribyteRate;
 
        if (DSCEnable != true)
                return dml_max(PixelClock / 4.0 * OutputBpp / 24.0, 25.0);
 
+       PixelWordRate = PixelClock /  (OutputFormat == dm_444 ? 1 : 2);
+       HCActive = dml_ceil(DSCSlices * dml_ceil(OutputBpp *
+                       dml_ceil(HActive / DSCSlices, 1) / 8.0, 1) / 3.0, 1);
+       HCBlank = 64 + 32 *
+                       dml_ceil(AudioRate *  (AudioLayout == 1 ? 1 : 0.25) * HTotal / (PixelClock * 1000), 1);
+       AverageTribyteRate = PixelWordRate * (HCActive + HCBlank) / HTotal;
+       HActiveTribyteRate = PixelWordRate * HCActive / HActive;
        return dml_max4(PixelWordRate / 4.0, AverageTribyteRate / 4.0, HActiveTribyteRate / 4.0, 25.0) * 1.002;
 }