[PATCH AUTOSEL 4.19 27/68] drm/amdgpu: Add amdgpu "max bpc" connector property (v2)

[PATCH AUTOSEL 4.19 27/68] drm/amdgpu: Add amdgpu "max bpc" connector property (v2)

[Sasha Levin]

From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

[ Upstream commit 69756c6ff0de478c10100481f16c966dde3b5339 ]

[Why]
Many panels support more than 8bpc but some modes are unavailable while
running at greater than 8bpc due to DP/HDMI bandwidth constraints.

Support for more than 8bpc was added recently in the driver but it
defaults to the maximum supported bpc - locking out these modes.

This should be a user configurable option such that the user can select
what bpc configuration they would like.

[How]
This patch introduces the "max bpc" amdgpu driver specific connector
property so the user can limit the maximum bpc. It ranges from 8 to 16.

This doesn't directly set the preferred bpc for the panel since it
follows Intel's existing driver conventions.

This proprety should be removed once common drm support for max bpc
lands.

v2: rebase on upstream (Alex)

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 7 +++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h    | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 6748cd7fc129..686a26de50f9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -626,6 +626,13 @@ int amdgpu_display_modeset_create_props(struct amdgpu_device *adev)
 					 "dither",
 					 amdgpu_dither_enum_list, sz);
 
+	if (amdgpu_device_has_dc_support(adev)) {
+		adev->mode_info.max_bpc_property =
+			drm_property_create_range(adev->ddev, 0, "max bpc", 8, 16);
+		if (!adev->mode_info.max_bpc_property)
+			return -ENOMEM;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
index b9e9e8b02fb7..d1b4d9b6aae0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -339,6 +339,8 @@ struct amdgpu_mode_info {
 	struct drm_property *audio_property;
 	/* FMT dithering */
 	struct drm_property *dither_property;
+	/* maximum number of bits per channel for monitor color */
+	struct drm_property *max_bpc_property;
 	/* hardcoded DFP edid from BIOS */
 	struct edid *bios_hardcoded_edid;
 	int bios_hardcoded_edid_size;
-- 
2.17.1

[PATCH AUTOSEL 4.19 28/68] drm/amd/display: Support amdgpu "max bpc" connector property (v2)

[Sasha Levin]

From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

[ Upstream commit 07e3a1cfb0568b6d8d7862077029af96af6690ea ]

[Why]
Many panels support more than 8bpc but some modes are unavailable while
running at greater than 8bpc due to DP/HDMI bandwidth constraints.

Support for more than 8bpc was added recently in the driver but it
defaults to the maximum supported bpc - locking out these modes.

This should be a user configurable option such that the user can select
what bpc configuration they would like.

[How]
This patch adds support for getting and setting the amdgpu driver
specific "max bpc" property on the connector.

It also adds support for limiting the output bpc based on the property
value. The default limitation is the lowest value in the range, 8bpc.
This was the old value before the range was uncapped.

This patch should be updated/replaced later once common drm support
for max bpc lands.

Bugzilla: https://bugs.freedesktop.org/108542
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201585
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200645
Fixes: e03fd3f300f6 ("drm/amd/display: Do not limit color depth to 8bpc")

v2: rebase on upstream (Alex)

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    | 16 ++++++++++++++++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h    |  1 +
 2 files changed, 17 insertions(+)

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 ef5c6af4d964..299def84e69c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2213,8 +2213,15 @@ static void update_stream_scaling_settings(const struct drm_display_mode *mode,
 static enum dc_color_depth
 convert_color_depth_from_display_info(const struct drm_connector *connector)
 {
+	struct dm_connector_state *dm_conn_state =
+		to_dm_connector_state(connector->state);
 	uint32_t bpc = connector->display_info.bpc;
 
+	/* TODO: Remove this when there's support for max_bpc in drm */
+	if (dm_conn_state && bpc > dm_conn_state->max_bpc)
+		/* Round down to nearest even number. */
+		bpc = dm_conn_state->max_bpc - (dm_conn_state->max_bpc & 1);
+
 	switch (bpc) {
 	case 0:
 		/* Temporary Work around, DRM don't parse color depth for
@@ -2796,6 +2803,9 @@ int amdgpu_dm_connector_atomic_set_property(struct drm_connector *connector,
 	} else if (property == adev->mode_info.underscan_property) {
 		dm_new_state->underscan_enable = val;
 		ret = 0;
+	} else if (property == adev->mode_info.max_bpc_property) {
+		dm_new_state->max_bpc = val;
+		ret = 0;
 	}
 
 	return ret;
@@ -2838,6 +2848,9 @@ int amdgpu_dm_connector_atomic_get_property(struct drm_connector *connector,
 	} else if (property == adev->mode_info.underscan_property) {
 		*val = dm_state->underscan_enable;
 		ret = 0;
+	} else if (property == adev->mode_info.max_bpc_property) {
+		*val = dm_state->max_bpc;
+		ret = 0;
 	}
 	return ret;
 }
@@ -3658,6 +3671,9 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 	drm_object_attach_property(&aconnector->base.base,
 				adev->mode_info.underscan_vborder_property,
 				0);
+	drm_object_attach_property(&aconnector->base.base,
+				adev->mode_info.max_bpc_property,
+				0);
 
 }
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index aba2c5c1d2f8..74aedcffc4bb 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -213,6 +213,7 @@ struct dm_connector_state {
 	enum amdgpu_rmx_type scaling;
 	uint8_t underscan_vborder;
 	uint8_t underscan_hborder;
+	uint8_t max_bpc;
 	bool underscan_enable;
 	struct mod_freesync_user_enable user_enable;
 	bool freesync_capable;
-- 
2.17.1