drm/i915: Don't call encoder's get_config unless encoder is active

[linux-imx.git] / drivers / gpu / drm / i915 / intel_display.c

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 76b034be2c7c3669c07198fcc196faf295ca9f0e..e38b457866535925acaf054b549f5bb07ce180f7 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8269,9 +8269,11 @@ check_crtc_state(struct drm_device *dev)
 
                list_for_each_entry(encoder, &dev->mode_config.encoder_list,
                                    base.head) {
+                       enum pipe pipe;
                        if (encoder->base.crtc != &crtc->base)
                                continue;
-                       if (encoder->get_config)
+                       if (encoder->get_config &&
+                           encoder->get_hw_state(encoder, &pipe))
                                encoder->get_config(encoder, &pipe_config);
                }
 
@@ -9400,6 +9402,17 @@ static void quirk_invert_brightness(struct drm_device *dev)
        DRM_INFO("applying inverted panel brightness quirk\n");
 }
 
+/*
+ * Some machines (Dell XPS13) suffer broken backlight controls if
+ * BLM_PCH_PWM_ENABLE is set.
+ */
+static void quirk_no_pcm_pwm_enable(struct drm_device *dev)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       dev_priv->quirks |= QUIRK_NO_PCH_PWM_ENABLE;
+       DRM_INFO("applying no-PCH_PWM_ENABLE quirk\n");
+}
+
 struct intel_quirk {
        int device;
        int subsystem_vendor;
@@ -9469,6 +9482,11 @@ static struct intel_quirk intel_quirks[] = {
 
        /* Acer Aspire 4736Z */
        { 0x2a42, 0x1025, 0x0260, quirk_invert_brightness },
+
+       /* Dell XPS13 HD Sandy Bridge */
+       { 0x0116, 0x1028, 0x052e, quirk_no_pcm_pwm_enable },
+       /* Dell XPS13 HD and XPS13 FHD Ivy Bridge */
+       { 0x0166, 0x1028, 0x058b, quirk_no_pcm_pwm_enable },
 };
 
 static void intel_init_quirks(struct drm_device *dev)