linux.git/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h, branch master Linux kernel source tree drm/amd/display: Test panel power savings sysfs 2026-07-15T13:15:39+00:00 Alex Hung alex.hung@amd.com 2026-06-30T00:43:57+00:00 db546ee97153c95ea719da015cf002f970175605 [WHAT] Add KUnit coverage using a DRM-managed connector fixture. Tests cover show() mapping immediate-disable to 0 and reporting an active ABM level, and store() handling the disable mapping, the forbidden update, invalid text, and out-of-range input. show() writes through a page-backed buffer because sysfs_emit() requires one. Assisted-by: Copilot:Claude-Opus-4.8 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: George Zhang <george.zhang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
[WHAT]
Add KUnit coverage using a DRM-managed connector fixture.

Tests cover show() mapping immediate-disable to 0 and reporting an active
ABM level, and store() handling the disable mapping, the forbidden update,
invalid text, and out-of-range input. show() writes through a page-backed
buffer because sysfs_emit() requires one.

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Test backlight level readback path 2026-07-15T13:15:39+00:00 Alex Hung alex.hung@amd.com 2026-06-30T00:39:36+00:00 c50a4305dfc2e91681c3991af3006ccbb2ec0eb7 [WHAT] Add KUnit coverage for the backlight level read path. A faked link_service vtable returns canned PWM and AUX brightness values, letting the tests verify both the successful readback and the DC_ERROR/AUX-failure fallbacks to the cached brightness, plus the get_brightness() device-index wrapper. Assisted-by: Copilot:Claude-Opus-4.8 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: George Zhang <george.zhang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
[WHAT]
Add KUnit coverage for the backlight level read path.

A faked link_service vtable returns canned PWM and AUX brightness values,
letting the tests verify both the successful readback and the
DC_ERROR/AUX-failure fallbacks to the cached brightness, plus the
get_brightness() device-index wrapper.

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Test backlight level programming path 2026-07-15T13:15:39+00:00 Alex Hung alex.hung@amd.com 2026-06-30T00:37:52+00:00 ee486cb800915b2fc7ecfd108982198045860060 [WHAT] Add KUnit coverage for the backlight level write path in amdgpu_dm_backlight.c. Tests cover stream lookup hit/miss, the connector-off and no-stream early returns, and the AUX/PWM/idle-reallow programming branches. The DC programming calls stay safe by injecting a NULL power module and keeping idle optimizations a no-op via disable_idle_power_optimizations. Assisted-by: Copilot:Claude-Opus-4.8 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: George Zhang <george.zhang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
[WHAT]
Add KUnit coverage for the backlight level write path in
amdgpu_dm_backlight.c.

Tests cover stream lookup hit/miss, the connector-off and no-stream early
returns, and the AUX/PWM/idle-reallow programming branches. The DC
programming calls stay safe by injecting a NULL power module and keeping
idle optimizations a no-op via disable_idle_power_optimizations.

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Extract backlight helpers for KUnit tests 2026-07-01T15:31:16+00:00 Alex Hung alex.hung@amd.com 2026-06-12T23:20:27+00:00 703e3ae7565d0b7eeaa91d679b4ef3e38f257735 [WHAT] Extract shared backlight device index lookup and property setup into testable helpers. The duplicated bd-to-index scan in update_status/get_brightness is replaced by amdgpu_dm_backlight_get_device_index(), and the inline backlight_properties calculation is replaced by amdgpu_dm_backlight_fill_props(). Add KUnit coverage for both new helpers. Keep the runtime power_supply_is_system_supplied() call at the caller so the helpers remain pure and deterministic under test. Assisted-by: Copilot:GPT-5.5 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: George Zhang <george.zhang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
[WHAT]
Extract shared backlight device index lookup and property
setup into testable helpers. The duplicated bd-to-index
scan in update_status/get_brightness is replaced by
amdgpu_dm_backlight_get_device_index(), and the inline
backlight_properties calculation is replaced by
amdgpu_dm_backlight_fill_props().

Add KUnit coverage for both new helpers. Keep the runtime
power_supply_is_system_supplied() call at the caller so
the helpers remain pure and deterministic under test.

Assisted-by: Copilot:GPT-5.5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Move backlight macros to backlight header 2026-06-17T20:17:13+00:00 Alex Hung alex.hung@amd.com 2026-06-05T16:37:38+00:00 75ac474209514d2aa1b9bf43d391bcafa50384d0 [WHAT] Move AMDGPU_DM_DEFAULT_MIN_BACKLIGHT, AMDGPU_DM_DEFAULT_MAX_BACKLIGHT, AMDGPU_DM_MIN_SPREAD, and AUX_BL_DEFAULT_TRANSITION_TIME_MS from amdgpu_dm_backlight.c to amdgpu_dm_backlight.h so they can be reused by KUnit tests. Update the test file to use these macros instead of hardcoded literal values. Assisted-by: Copilot:Claude-Opus-4.6 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
[WHAT]
Move AMDGPU_DM_DEFAULT_MIN_BACKLIGHT, AMDGPU_DM_DEFAULT_MAX_BACKLIGHT,
AMDGPU_DM_MIN_SPREAD, and AUX_BL_DEFAULT_TRANSITION_TIME_MS from
amdgpu_dm_backlight.c to amdgpu_dm_backlight.h so they can be reused
by KUnit tests. Update the test file to use these macros instead of
hardcoded literal values.

Assisted-by: Copilot:Claude-Opus-4.6
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Add KUnit tests for amdgpu_dm_backlight 2026-06-17T20:16:03+00:00 Alex Hung alex.hung@amd.com 2026-04-30T02:57:54+00:00 179b22085ef0177fa3c78afa2858100d59f5a991 Add KUnit tests for the backlight helpers in amdgpu_dm_backlight.c. Tests cover: - amdgpu_dm_update_backlight_caps(): short-circuit on populated caps and default value assignment - get_brightness_range(): NULL, PWM-only, and AUX backlight paths - convert_brightness_to_user(): minimum clamp, maximum passthrough, and mid-range rescaling - convert_brightness_from_user(): linear rescaling, AUX path, and custom-curve mapping - convert_custom_brightness(): exact match, below-first, interpolation, above-last, single data point, zero lower luminance, and the debug-mask and no-data-point guards - amdgpu_dm_update_connector_ext_caps(): negative bl_idx and non-eDP early returns, OLED defaults, luminance range copy, and the amdgpu_backlight force-AUX/force-PWM overrides - amdgpu_dm_should_create_sysfs(): forced ABM, non-eDP, missing backlight index, and AUX vs PWM backlight - amdgpu_dm_setup_backlight_device(): non-eDP/LVDS skip, disconnected link skip, eDP-count limit, and the successful eDP setup path Assisted-by: Copilot:Claude-Opus-4.8 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Add KUnit tests for the backlight helpers in amdgpu_dm_backlight.c.

Tests cover:
- amdgpu_dm_update_backlight_caps(): short-circuit on populated caps
  and default value assignment
- get_brightness_range(): NULL, PWM-only, and AUX backlight paths
- convert_brightness_to_user(): minimum clamp, maximum passthrough,
  and mid-range rescaling
- convert_brightness_from_user(): linear rescaling, AUX path, and
  custom-curve mapping
- convert_custom_brightness(): exact match, below-first, interpolation,
  above-last, single data point, zero lower luminance, and the
  debug-mask and no-data-point guards
- amdgpu_dm_update_connector_ext_caps(): negative bl_idx and non-eDP
  early returns, OLED defaults, luminance range copy, and the
  amdgpu_backlight force-AUX/force-PWM overrides
- amdgpu_dm_should_create_sysfs(): forced ABM, non-eDP, missing
  backlight index, and AUX vs PWM backlight
- amdgpu_dm_setup_backlight_device(): non-eDP/LVDS skip, disconnected
  link skip, eDP-count limit, and the successful eDP setup path

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amd/display: Extract backlight code to amdgpu_dm_backlight 2026-06-17T20:14:47+00:00 Alex Hung alex.hung@amd.com 2026-04-24T00:34:52+00:00 f5165625b8b27a46993e0c55b4468bd4e215f7c6 Move backlight-related functions from amdgpu_dm.c into a new amdgpu_dm_backlight.c file to improve code organization and reduce the size of the monolithic amdgpu_dm.c. No functional change intended. Assisted-by: Copilot:Claude-Opus-4.6 Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Move backlight-related functions from amdgpu_dm.c into a new
amdgpu_dm_backlight.c file to improve code organization and
reduce the size of the monolithic amdgpu_dm.c.

No functional change intended.

Assisted-by: Copilot:Claude-Opus-4.6
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>