5 files changed, 26 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bae38acf44dc..5908cd563400 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3478,8 +3478,11 @@ static bool intel_crtc_mode_fixup(struct drm_crtc *crtc,
 			return false;
 	}
 
-	/* All interlaced capable intel hw wants timings in frames. */
-	drm_mode_set_crtcinfo(adjusted_mode, 0);
+	/* All interlaced capable intel hw wants timings in frames. Note though
+	 * that intel_lvds_mode_fixup does some funny tricks with the crtc
+	 * timings, so we need to be careful not to clobber these.*/
+	if (!(adjusted_mode->private_flags & INTEL_MODE_CRTC_TIMINGS_SET))
+		drm_mode_set_crtcinfo(adjusted_mode, 0);
 
 	return true;
 }
@@ -7465,7 +7468,13 @@ static int intel_gen6_queue_flip(struct drm_device *dev,
 	OUT_RING(fb->pitches[0] | obj->tiling_mode);
 	OUT_RING(obj->gtt_offset);
 
-	pf = I915_READ(PF_CTL(intel_crtc->pipe)) & PF_ENABLE;
+	/* Contrary to the suggestions in the documentation,
+	 * "Enable Panel Fitter" does not seem to be required when page
+	 * flipping with a non-native mode, and worse causes a normal
+	 * modeset to fail.
+	 * pf = I915_READ(PF_CTL(intel_crtc->pipe)) & PF_ENABLE;
+	 */
+	pf = 0;
 	pipesrc = I915_READ(PIPESRC(intel_crtc->pipe)) & 0x0fff0fff;
 	OUT_RING(pf | pipesrc);
 	ADVANCE_LP_RING();
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5a14149b3794..715afa153025 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -105,6 +105,10 @@
 #define INTEL_MODE_PIXEL_MULTIPLIER_SHIFT (0x0)
 #define INTEL_MODE_PIXEL_MULTIPLIER_MASK (0xf << INTEL_MODE_PIXEL_MULTIPLIER_SHIFT)
 #define INTEL_MODE_DP_FORCE_6BPC (0x10)
+/* This flag must be set by the encoder's mode_fixup if it changes the crtc
+ * timings in the mode to prevent the crtc fixup from overwriting them.
+ * Currently only lvds needs that. */
+#define INTEL_MODE_CRTC_TIMINGS_SET (0x20)
 
 static inline void
 intel_mode_set_pixel_multiplier(struct drm_display_mode *mode,
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 19ecd78b8a2c..6e9ee33fd412 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -279,6 +279,8 @@ void intel_fb_restore_mode(struct drm_device *dev)
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_plane *plane;
 
+	mutex_lock(&dev->mode_config.mutex);
+
 	ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
 	if (ret)
 		DRM_DEBUG("failed to restore crtc mode\n");
@@ -286,4 +288,6 @@ void intel_fb_restore_mode(struct drm_device *dev)
 	/* Be sure to shut off any planes that may be active */
 	list_for_each_entry(plane, &config->plane_list, head)
 		plane->funcs->disable_plane(plane);
+
+	mutex_unlock(&dev->mode_config.mutex);
 }
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 95db2e988227..30e2c82101de 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -187,6 +187,8 @@ centre_horizontally(struct drm_display_mode *mode,
 
 	mode->crtc_hsync_start = mode->crtc_hblank_start + sync_pos;
 	mode->crtc_hsync_end = mode->crtc_hsync_start + sync_width;
+
+	mode->private_flags |= INTEL_MODE_CRTC_TIMINGS_SET;
 }
 
 static void
@@ -208,6 +210,8 @@ centre_vertically(struct drm_display_mode *mode,
 
 	mode->crtc_vsync_start = mode->crtc_vblank_start + sync_pos;
 	mode->crtc_vsync_end = mode->crtc_vsync_start + sync_width;
+
+	mode->private_flags |= INTEL_MODE_CRTC_TIMINGS_SET;
 }
 
 static inline u32 panel_fitter_scaling(u32 source, u32 target)
@@ -283,6 +287,8 @@ static bool intel_lvds_mode_fixup(struct drm_encoder *encoder,
 	for_each_pipe(pipe)
 		I915_WRITE(BCLRPAT(pipe), 0);
 
+	drm_mode_set_crtcinfo(adjusted_mode, 0);
+
 	switch (intel_lvds->fitting_mode) {
 	case DRM_MODE_SCALE_CENTER:
 		/*
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 230a141dbea3..48177ec4720e 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -47,8 +47,6 @@ intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
 	adjusted_mode->vtotal = fixed_mode->vtotal;
 
 	adjusted_mode->clock = fixed_mode->clock;
-
-	drm_mode_set_crtcinfo(adjusted_mode, 0);
 }
 
 /* adjusted_mode has been preset to be the panel's fixed mode */