[PATCH 16/16] drm/amd/display: Don't restrict bpc to 8 bpc

Harry Wentland harry.wentland at amd.com
Mon Dec 12 18:21:37 UTC 2022


This will let us pass kms_hdr.bpc_switch.

I don't see any good reasons why we still need to
limit bpc to 8 bpc and doing so is problematic when
we enable HDR.

If I remember correctly there might have been some
displays out there where the advertised link bandwidth
was not large enough to drive the default timing at
max bpc. This would leave to an atomic commit/check
failure which should really be handled in compositors
with some sort of fallback mechanism.

If this somehow turns out to still be an issue I
suggest we add a module parameter to allow users to
limit the max_bpc to a desired value.

Signed-off-by: Harry Wentland <harry.wentland at amd.com>
Cc: Pekka Paalanen <ppaalanen at gmail.com>
Cc: Sebastian Wick <sebastian.wick at redhat.com>
Cc: Vitaly.Prosyak at amd.com
Cc: Uma Shankar <uma.shankar at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Joshua Ashton <joshua at froggi.es>
Cc: dri-devel at lists.freedesktop.org
Cc: amd-gfx at lists.freedesktop.org
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index d0c071000a5d..396e345f5d6b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7115,7 +7115,7 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 		drm_connector_attach_max_bpc_property(&aconnector->base, 8, 16);
 
 	/* This defaults to the max in the range, but we want 8bpc for non-edp. */
-	aconnector->base.state->max_bpc = (connector_type == DRM_MODE_CONNECTOR_eDP) ? 16 : 8;
+	aconnector->base.state->max_bpc = 16;
 	aconnector->base.state->max_requested_bpc = aconnector->base.state->max_bpc;
 
 	if (connector_type == DRM_MODE_CONNECTOR_eDP &&
-- 
2.38.1



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