#define AMDGPU_DM_DEFAULT_MIN_BACKLIGHT 12
#define AMDGPU_DM_DEFAULT_MAX_BACKLIGHT 255
+#define AMDGPU_DM_MIN_SPREAD ((AMDGPU_DM_DEFAULT_MAX_BACKLIGHT - AMDGPU_DM_DEFAULT_MIN_BACKLIGHT) / 2)
#define AUX_BL_DEFAULT_TRANSITION_TIME_MS 50
static void amdgpu_dm_update_backlight_caps(struct amdgpu_display_manager *dm,
return;
amdgpu_acpi_get_backlight_caps(&caps);
+
+ /* validate the firmware value is sane */
+ if (caps.caps_valid) {
+ int spread = caps.max_input_signal - caps.min_input_signal;
+
+ if (caps.max_input_signal > AMDGPU_DM_DEFAULT_MAX_BACKLIGHT ||
+ caps.min_input_signal < AMDGPU_DM_DEFAULT_MIN_BACKLIGHT ||
+ spread > AMDGPU_DM_DEFAULT_MAX_BACKLIGHT ||
+ spread < AMDGPU_DM_MIN_SPREAD) {
+ DRM_DEBUG_KMS("DM: Invalid backlight caps: min=%d, max=%d\n",
+ caps.min_input_signal, caps.max_input_signal);
+ caps.caps_valid = false;
+ }
+ }
+
if (caps.caps_valid) {
dm->backlight_caps[bl_idx].caps_valid = true;
if (caps.aux_support)