drm/i915: Check backlight type while doing eDP backlight initializaiton

If LFP backlight type setting from VBT was "VESA eDP AUX Interface".
Driver should check panel capability and try to initialize aux backlight.
No matter i915_modparams.enable_dpcd_backlight was enabled or not.

v2: access dev_priv->vbt.backlight.type directly and remove unused function.
v3: 1. Modify i915.enable_dpcd_backlight type from bool to int and give default
       value as 0 (disable).
    2. Add a judgement to check LFP backlight type was aux interface or not.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1561045456-12171-1-git-send-email-shawn.c.lee@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h
index 4e42cfaf61a7e3903ba6d5b57b3cd96a731c4163..0b7be6389a07b1c9ca944c6ca756f44a263fe5cb 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.h
+++ b/drivers/gpu/drm/i915/display/intel_bios.h
@@ -42,6 +42,7 @@ 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 {

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 7ded95a334db5b89bba90def1e1098e98a79f8b2..6b0b73479fb8e652a0c555da289334ce3da674c7 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -264,8 +264,11 @@ 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))

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 5b07766a1c26ef7aa2c15f7548b22cdcf36c4d9f..296452f9efe4cbbf0ae556dcc2a26ee33af32c22 100644 (file)
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -169,8 +169,9 @@ 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,

diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index a4770ce46bd2407ada2b361e0efd242814000c9e..d29ade3b7de6b12d0bbbd72754f457e032896505 100644 (file)
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -64,6 +64,7 @@ struct drm_printer;
        param(int, reset, 2) \
        param(unsigned int, inject_load_failure, 0) \
        param(int, fastboot, -1) \
+       param(int, enable_dpcd_backlight, 0) \
        param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE) \
        /* leave bools at the end to not create holes */ \
        param(bool, alpha_support, IS_ENABLED(CONFIG_DRM_I915_ALPHA_SUPPORT)) \
@@ -76,7 +77,6 @@ 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;