drm/i915: keep backlight_enable on until turn eDP display off

This workaround is specific for a particular panel on Google
chromebook project. When user space daemon enter idle state.
It request adjust brightness to 0, turn backlight_enable signal
off and keep eDP main link active.

On general LCD, this behavior might not be a problem.
But on this panel, its tcon would expect source to execute
full eDP power off sequence after drop backlight_enable signal.
Without eDP power off sequence. Even source try to turn
backlight_enable signal on and restore proper brightness level.
This panel is not able to light on again.

This WA ignored the request from user space daemon to disable
backlight_enable signal and keep it on always. When user space
request kernel to turn eDP display off, kernel driver still
can control backlight_enable signal properly. It would not
impact standard eDP power off sequence.

v2: 1. modify the quirk name and debug messages.
    2. unregister backlight.power callback for specific device.
v3: 1. modify debug output messages.
    2. use DMI_EXACT_MATCH instead of DMI_MATCH.

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@linux.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/20210624053932.21037-1-shawn.c.lee@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 6cc03b9e4321aa5376d8fa4de41e86ed507542b1..d3312b9bcc6f5f77d9765b9767b8fa2b08314554 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5238,7 +5238,8 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
        }
 
        intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode);
-       intel_connector->panel.backlight.power = intel_pps_backlight_power;
+       if (!(dev_priv->quirks & QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
+               intel_connector->panel.backlight.power = intel_pps_backlight_power;
        intel_panel_setup_backlight(connector, pipe);
 
        if (fixed_mode) {

diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/i915/display/intel_quirks.c
index 98dd787b00e3924d953cd1fa71386a1d5bac0e37..8a52b7a1677466dd22f68ab25890204623dc6bf4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_quirks.c
+++ b/drivers/gpu/drm/i915/display/intel_quirks.c
@@ -53,6 +53,12 @@ static void quirk_increase_ddi_disabled_time(struct drm_i915_private *i915)
        drm_info(&i915->drm, "Applying Increase DDI Disabled quirk\n");
 }
 
+static void quirk_no_pps_backlight_power_hook(struct drm_i915_private *i915)
+{
+       i915->quirks |= QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK;
+       drm_info(&i915->drm, "Applying no pps backlight power quirk\n");
+}
+
 struct intel_quirk {
        int device;
        int subsystem_vendor;
@@ -72,6 +78,12 @@ static int intel_dmi_reverse_brightness(const struct dmi_system_id *id)
        return 1;
 }
 
+static int intel_dmi_no_pps_backlight(const struct dmi_system_id *id)
+{
+       DRM_INFO("No pps backlight support on %s\n", id->ident);
+       return 1;
+}
+
 static const struct intel_dmi_quirk intel_dmi_quirks[] = {
        {
                .dmi_id_list = &(const struct dmi_system_id[]) {
@@ -96,6 +108,28 @@ static const struct intel_dmi_quirk intel_dmi_quirks[] = {
                },
                .hook = quirk_invert_brightness,
        },
+       {
+               .dmi_id_list = &(const struct dmi_system_id[]) {
+                       {
+                               .callback = intel_dmi_no_pps_backlight,
+                               .ident = "Google Lillipup sku524294",
+                               .matches = {DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Google"),
+                                           DMI_EXACT_MATCH(DMI_BOARD_NAME, "Lindar"),
+                                           DMI_EXACT_MATCH(DMI_PRODUCT_SKU, "sku524294"),
+                               },
+                       },
+                       {
+                               .callback = intel_dmi_no_pps_backlight,
+                               .ident = "Google Lillipup sku524295",
+                               .matches = {DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Google"),
+                                           DMI_EXACT_MATCH(DMI_BOARD_NAME, "Lindar"),
+                                           DMI_EXACT_MATCH(DMI_PRODUCT_SKU, "sku524295"),
+                               },
+                       },
+                       { }
+               },
+               .hook = quirk_no_pps_backlight_power_hook,
+       },
 };
 
 static struct intel_quirk intel_quirks[] = {

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index eb3d685cbd22be08e3ff2f8c979dff924f7cd2fe..a937d75112784d3f6d774cbf8eca5426189d1c51 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -466,6 +466,7 @@ struct i915_drrs {
 #define QUIRK_PIN_SWIZZLED_PAGES (1<<5)
 #define QUIRK_INCREASE_T12_DELAY (1<<6)
 #define QUIRK_INCREASE_DDI_DISABLED_TIME (1<<7)
+#define QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK (1<<8)
 
 struct intel_fbdev;
 struct intel_fbc_work;