diff mbox series

[6/7] drm/i915/dp: Ensure hactive is divisible by slice count

Message ID 20241027134557.862036-7-ankit.k.nautiyal@intel.com (mailing list archive)
State New
Headers show
Series Add support for 3 VDSC engines 12 slices | expand

Commit Message

Ankit Nautiyal Oct. 27, 2024, 1:45 p.m. UTC 
According to the DSC spec, the slice width should be chosen such that
the picture width (hactive) is evenly divisible by the slice width.
If not, extra pixels (padding) must be added to the last slice to
ensure all slices have the same width.

Currently, we do not support handling these extra pixels.
Therefore, select a slice count that evenly divides the hactive
(slice_width = hactive / slice_count).

This check is already implemented for DSI, where the slice count is
selected from the BIOS.

For DP, currently with 1, 2, 4 slices per pipe it is unlikely to have
slice count not being able to divide hactive, but with 3 DSC engines
and 3 slices, we can have such cases. Adding this check prepares for
future scenarios where such configurations might be used.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index dbb1d75c0576..d7d42eac4be3 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1038,6 +1038,9 @@  u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
 		if (num_joined_pipes > 1 && valid_dsc_slicecount[i] < 2)
 			continue;
 
+		if (mode_hdisplay % test_slice_count)
+			continue;
+
 		if (min_slice_count <= test_slice_count)
 			return test_slice_count;
 	}