[Why] If the DC API fails to return actual brightness when backlight control API requests it, then the wrong value may be returned.
[How] Change return type of amdgpu_dm_backlight_get_level() to an integer and pass an error code up to the caller. Signed-off-by: Mario Limonciello <[email protected]> --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c | 13 +++++++++---- .../drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h | 2 +- .../amdgpu_dm/tests/amdgpu_dm_backlight_test.c | 4 ++-- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c index 45e1732a5b041..64a963c218c8b 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c @@ -372,7 +372,7 @@ int amdgpu_dm_backlight_update_status(struct backlight_device *bd) EXPORT_IF_KUNIT(amdgpu_dm_backlight_update_status); STATIC_IFN_KUNIT -u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) +int amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) { int ret; struct amdgpu_dm_backlight_caps caps; @@ -385,14 +385,14 @@ u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) u32 avg, peak; if (!dc_link_get_backlight_level_nits(link, &avg, &peak)) - return dm->brightness[bl_idx]; + return -EINVAL; return convert_brightness_to_user(&caps, avg); } ret = dc_link_get_backlight_level(link); if (ret == DC_ERROR_UNEXPECTED) - return dm->brightness[bl_idx]; + return -EINVAL; return convert_brightness_to_user(&caps, ret); } @@ -403,8 +403,13 @@ int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd) { struct amdgpu_display_manager *dm = bl_get_data(bd); int i = amdgpu_dm_backlight_get_device_index(dm, bd); + int ret; + + ret = amdgpu_dm_backlight_get_level(dm, i); + if (ret < 0) + return dm->brightness[i]; - return amdgpu_dm_backlight_get_level(dm, i); + return ret; } EXPORT_IF_KUNIT(amdgpu_dm_backlight_get_brightness); diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h index 9ad888d3ae7b2..891749322191c 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h @@ -57,7 +57,7 @@ void amdgpu_dm_validate_backlight_caps(struct amdgpu_display_manager *dm, int bl struct dc_stream_state *dm_find_stream_with_link(struct amdgpu_display_manager *dm, struct dc_link *link); int amdgpu_dm_backlight_update_status(struct backlight_device *bd); -u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx); +int amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx); int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd); ssize_t panel_power_savings_show(struct device *device, struct device_attribute *attr, diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c index 5221050dec2f1..b21850788f36f 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c @@ -382,7 +382,7 @@ static void dm_test_backlight_get_level_pwm_error(struct kunit *test) dm->brightness[0] = 4321; dm->backlight_link[0] = link; - KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), 4321U); + KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), -EINVAL); } /** @@ -424,7 +424,7 @@ static void dm_test_backlight_get_level_aux_error(struct kunit *test) caps->caps_valid = true; caps->aux_support = true; - KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), 6789U); + KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), -EINVAL); } /** -- 2.43.0
