[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]> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index d99617c9bbb9..de9b29ad6cab 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5427,7 +5427,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd) return 0; } -static u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, +static int amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) { int ret; @@ -5441,14 +5441,14 @@ static u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, 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); } @@ -5456,7 +5456,7 @@ static u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd) { struct amdgpu_display_manager *dm = bl_get_data(bd); - int i; + int i, ret; for (i = 0; i < dm->num_of_edps; i++) { if (bd == dm->backlight_dev[i]) @@ -5464,7 +5464,12 @@ static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd) } if (i >= AMDGPU_DM_MAX_NUM_EDP) i = 0; - return amdgpu_dm_backlight_get_level(dm, i); + + ret = amdgpu_dm_backlight_get_level(dm, i); + if (ret < 0) + return dm->brightness[i]; + + return ret; } static const struct backlight_ops amdgpu_dm_backlight_ops = { -- 2.54.0
