@@ -164,8 +164,9 @@ i915_param_named_unsafe(inject_load_failure, uint, 0400,
"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
#endif
-i915_param_named(enable_dpcd_backlight, bool, 0600,
- "Enable support for DPCD backlight control (default:false)");
+i915_param_named(enable_dpcd_backlight, int, 0600,
+ "Enable support for DPCD backlight control"
+ "(-1=use per-VBT LFP backlight type setting, 0=disabled [default], 1=enabled)");
#if IS_ENABLED(CONFIG_DRM_I915_GVT)
i915_param_named(enable_gvt, bool, 0400,
@@ -54,6 +54,7 @@ struct drm_printer;
param(int, edp_vswing, 0) \
param(int, reset, 2) \
param(unsigned int, inject_load_failure, 0) \
+ param(int, enable_dpcd_backlight, 0) \
/* leave bools at the end to not create holes */ \
param(bool, alpha_support, IS_ENABLED(CONFIG_DRM_I915_ALPHA_SUPPORT)) \
param(bool, enable_hangcheck, true) \
@@ -66,7 +67,6 @@ struct drm_printer;
param(bool, verbose_state_checks, true) \
param(bool, nuclear_pageflip, false) \
param(bool, enable_dp_mst, true) \
- param(bool, enable_dpcd_backlight, false) \
param(bool, enable_gvt, false)
#define MEMBER(T, member, ...) T member;
@@ -36,6 +36,7 @@ enum intel_backlight_type {
INTEL_BACKLIGHT_DISPLAY_DDI,
INTEL_BACKLIGHT_DSI_DCS,
INTEL_BACKLIGHT_PANEL_DRIVER_INTERFACE,
+ INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE,
};
struct edp_power_seq {
@@ -324,8 +324,11 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
{
struct intel_panel *panel = &intel_connector->panel;
+ struct drm_i915_private *dev_priv = to_i915(intel_connector->base.dev);
- if (!i915_modparams.enable_dpcd_backlight)
+ if (i915_modparams.enable_dpcd_backlight == 0 ||
+ (i915_modparams.enable_dpcd_backlight == -1 &&
+ dev_priv->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE))
return -ENODEV;
if (!intel_dp_aux_display_control_capable(intel_connector))