drm/amd/display: Add Z8 allow states to z-state support list

[Why]
Even if we block Z9 based on crossover threshold it's possible to
allow for Z8.

[How]
There's support for this on DCN314, so update the support types to
include a z8 only and z8_z10 only state.

Update the decide_zstate_support function to allow for specifying
these modes based on the Z8 threshold.

DCN31 has z-state disabled, but still update the legacy code to
map z8_only = disallow and z10_z8_only = z10_only to keep the support
the same.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 578ee5ec1ccc..1066bb8b0bb4 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -493,6 +493,8 @@ enum dcn_pwr_state {
 enum dcn_zstate_support_state {
 	DCN_ZSTATE_SUPPORT_UNKNOWN,
 	DCN_ZSTATE_SUPPORT_ALLOW,
+	DCN_ZSTATE_SUPPORT_ALLOW_Z8_ONLY,
+	DCN_ZSTATE_SUPPORT_ALLOW_Z8_Z10_ONLY,
 	DCN_ZSTATE_SUPPORT_ALLOW_Z10_ONLY,
 	DCN_ZSTATE_SUPPORT_DISALLOW,
 };