From e2306cc6a07aefc458982b3d7ae1e146515ed656 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Thu, 15 Nov 2018 17:19:12 -0500
Subject: drm/amdgpu: Add amdgpu "max bpc" connector property (v2)
Git-commit: e2306cc6a07aefc458982b3d7ae1e146515ed656
Patch-mainline: v5.0-rc1
References: bsc#1113956
[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>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
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 11723d8fffbd..0dc2c5c57015 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -338,6 +338,8 @@ 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;
--
2.20.1