Commit 7c209847 authored by Takashi Iwai's avatar Takashi Iwai Committed by Alex Deucher
Browse files

drm/amd/display: Add a backlight module option 

There seem devices that don't work with the aux channel backlight
control.  For allowing such users to test with the other backlight
control method, provide a new module option, aux_backlight, to specify
enabling or disabling the aux backport support explicitly.  As
default, the aux support is detected by the hardware capability.

v2: make the backlight option generic in case we add future
backlight types (Alex)

BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1180749
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1438


Reviewed-by: default avatarNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent f275e875

drivers/gpu/drm/amd/amdgpu/amdgpu.h

+1 −0
Original line number Diff line number Diff line
@@ -181,6 +181,7 @@ extern uint amdgpu_dc_feature_mask; 
extern uint amdgpu_freesync_vid_mode;

extern uint amdgpu_dc_debug_mask;

extern uint amdgpu_dm_abm_level;

extern int amdgpu_backlight;

extern struct amdgpu_mgpu_info mgpu_info;

extern int amdgpu_ras_enable;

extern uint amdgpu_ras_mask;

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

+4 −0
Original line number Diff line number Diff line
@@ -783,6 +783,10 @@ uint amdgpu_dm_abm_level; 
MODULE_PARM_DESC(abmlevel, "ABM level (0 = off (default), 1-4 = backlight reduction level) ");

module_param_named(abmlevel, amdgpu_dm_abm_level, uint, 0444);



int amdgpu_backlight = -1;

MODULE_PARM_DESC(backlight, "Backlight control (0 = pwm, 1 = aux, -1 auto (default))");

module_param_named(backlight, amdgpu_backlight, bint, 0444);



/**

 * DOC: tmz (int)

 * Trusted Memory Zone (TMZ) is a method to protect data being written

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

+5 −0
Original line number Diff line number Diff line
@@ -2324,6 +2324,11 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) 
	    caps->ext_caps->bits.hdr_aux_backlight_control == 1)

		caps->aux_support = true;



	if (amdgpu_backlight == 0)

		caps->aux_support = false;

	else if (amdgpu_backlight == 1)

		caps->aux_support = true;



	/* From the specification (CTA-861-G), for calculating the maximum

	 * luminance we need to use:

	 *	Luminance = 50*2**(CV/32)