1 files changed, 44 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3da9c0f9e948..248128126422 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -15415,16 +15415,45 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc,
         }
 }
 
+static bool has_bogus_dpll_config(const struct intel_crtc_state *crtc_state)
+{
+        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
+
+        /*
+         * Some SNB BIOSen (eg. ASUS K53SV) are known to misprogram
+         * the hardware when a high res displays plugged in. DPLL P
+         * divider is zero, and the pipe timings are bonkers. We'll
+         * try to disable everything in that case.
+         *
+         * FIXME would be nice to be able to sanitize this state
+         * without several WARNs, but for now let's take the easy
+         * road.
+         */
+        return IS_GEN6(dev_priv) &&
+                crtc_state->base.active &&
+                crtc_state->shared_dpll &&
+                crtc_state->port_clock == 0;
+}
+
 static void intel_sanitize_encoder(struct intel_encoder *encoder)
 {
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
         struct intel_connector *connector;
+        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
+        struct intel_crtc_state *crtc_state = crtc ?
+                to_intel_crtc_state(crtc->base.state) : NULL;
 
         /* We need to check both for a crtc link (meaning that the
          * encoder is active and trying to read from a pipe) and the
          * pipe itself being active. */
-        bool has_active_crtc = encoder->base.crtc &&
-                to_intel_crtc(encoder->base.crtc)->active;
+        bool has_active_crtc = crtc_state &&
+                crtc_state->base.active;
+
+        if (crtc_state && has_bogus_dpll_config(crtc_state)) {
+                DRM_DEBUG_KMS("BIOS has misprogrammed the hardware. Disabling pipe %c\n",
+                              pipe_name(crtc->pipe));
+                has_active_crtc = false;
+        }
 
         connector = intel_encoder_find_connector(encoder);
         if (connector && !has_active_crtc) {
@@ -15435,16 +15464,25 @@ static void intel_sanitize_encoder(struct intel_encoder *encoder)
                 /* Connector is active, but has no active pipe. This is
                  * fallout from our resume register restoring. Disable
                  * the encoder manually again. */
-                if (encoder->base.crtc) {
-                        struct drm_crtc_state *crtc_state = encoder->base.crtc->state;
+                if (crtc_state) {
+                        struct drm_encoder *best_encoder;
 
                         DRM_DEBUG_KMS("[ENCODER:%d:%s] manually disabled\n",
                                       encoder->base.base.id,
                                       encoder->base.name);
+
+                        /* avoid oopsing in case the hooks consult best_encoder */
+                        best_encoder = connector->base.state->best_encoder;
+                        connector->base.state->best_encoder = &encoder->base;
+
                         if (encoder->disable)
-                                encoder->disable(encoder, to_intel_crtc_state(crtc_state), connector->base.state);
+                                encoder->disable(encoder, crtc_state,
+                                                 connector->base.state);
                         if (encoder->post_disable)
-                                encoder->post_disable(encoder, to_intel_crtc_state(crtc_state), connector->base.state);
+                                encoder->post_disable(encoder, crtc_state,
+                                                      connector->base.state);
+
+                        connector->base.state->best_encoder = best_encoder;
                 }
                 encoder->base.crtc = NULL;