[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 (AMD) <[email protected]> --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c | 11 ++++++++--- .../drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h | 2 +- .../amdgpu_dm/tests/amdgpu_dm_backlight_test.c | 4 ++-- 3 files changed, 11 insertions(+), 6 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 e61bbc310f33c..fb2aaf0178c2b 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 @@ -363,7 +363,7 @@ 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; @@ -376,7 +376,7 @@ 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); } @@ -394,8 +394,13 @@ 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 07b75064847c7..72f1c8d861c8c 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 @@ -56,7 +56,7 @@ extern const struct attribute_group amdgpu_group; 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 7ca17f803f9d7..e03173d4e5bd8 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
