Commit 36d63ce5 authored by Mario Limonciello's avatar Mario Limonciello Committed by Alex Deucher
Browse files

drm/amd/display: Add a new dcdebugmask to allow turning off brightness curve 



Upgrading the kernel may cause some systems that were previously not using
a firmware specified brightness curve to use one.

In the event of problems with this curve (for example an interpolation
error) add a new dcdebugmask value that can be used to turn it off.  Also
add an info message to show that custom brightness curves are currently in
use.

Reviewed-by: default avatarAlex Hung <alex.hung@amd.com>
Link: https://lore.kernel.org/r/20250228185145.186319-6-mario.limonciello@amd.com


Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 578df37b

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+5 −0
Original line number Diff line number Diff line
@@ -4758,6 +4758,9 @@ static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *c 
	for (int i = 0; i < caps->data_points; i++) {

		u8 signal, lum;



		if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE)

			break;



		signal = caps->luminance_data[i].input_signal;

		lum = caps->luminance_data[i].luminance;
@@ -4942,6 +4945,8 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector) 
	} else

		props.brightness = AMDGPU_MAX_BL_LEVEL;



	if (caps.data_points && !(amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE))

		drm_info(drm, "Using custom brightness curve\n");

	props.max_brightness = AMDGPU_MAX_BL_LEVEL;

	props.type = BACKLIGHT_RAW;

drivers/gpu/drm/amd/include/amd_shared.h

+4 −0
Original line number Diff line number Diff line
@@ -354,6 +354,10 @@ enum DC_DEBUG_MASK { 
	 * @DC_DISABLE_SUBVP: If set, disable DCN Sub-Viewport feature in amdgpu driver.

	 */

	DC_DISABLE_SUBVP = 0x20000,

	/**

	 * @DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE: If set, disable support for custom brightness curves

	 */

	DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE = 0x40000,

};



enum amd_dpm_forced_level;