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-rw-r--r--drivers/gpu/drm/i915/display/intel_dp.c34
1 files changed, 23 insertions, 11 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 62cbab7402e9..bc7bb4eb4b50 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1415,6 +1415,28 @@ static int intel_dp_sink_dsc_version_minor(struct intel_dp *intel_dp)
DP_DSC_MINOR_SHIFT;
}
+static int intel_dp_get_slice_height(int vactive)
+{
+ int slice_height;
+
+ /*
+ * VDSC 1.2a spec in Section 3.8 Options for Slices implies that 108
+ * lines is an optimal slice height, but any size can be used as long as
+ * vertical active integer multiple and maximum vertical slice count
+ * requirements are met.
+ */
+ for (slice_height = 108; slice_height <= vactive; slice_height += 2)
+ if (vactive % slice_height == 0)
+ return slice_height;
+
+ /*
+ * Highly unlikely we reach here as most of the resolutions will end up
+ * finding appropriate slice_height in above loop but returning
+ * slice_height as 2 here as it should work with all resolutions.
+ */
+ return 2;
+}
+
static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
struct intel_crtc_state *crtc_state)
{
@@ -1433,17 +1455,7 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
vdsc_cfg->pic_height = crtc_state->hw.adjusted_mode.crtc_vdisplay;
- /*
- * Slice Height of 8 works for all currently available panels. So start
- * with that if pic_height is an integral multiple of 8. Eventually add
- * logic to try multiple slice heights.
- */
- if (vdsc_cfg->pic_height % 8 == 0)
- vdsc_cfg->slice_height = 8;
- else if (vdsc_cfg->pic_height % 4 == 0)
- vdsc_cfg->slice_height = 4;
- else
- vdsc_cfg->slice_height = 2;
+ vdsc_cfg->slice_height = intel_dp_get_slice_height(vdsc_cfg->pic_height);
ret = intel_dsc_compute_params(crtc_state);
if (ret)