3 files changed, 159 insertions, 34 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6f818fadcbe3..7d3309bc0fd2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1784,11 +1784,26 @@ static void igdng_crtc_dpms(struct drm_crtc *crtc, int mode)
 static void intel_crtc_dpms_overlay(struct intel_crtc *intel_crtc, bool enable)
 {
         struct intel_overlay *overlay;
+        int ret;
 
         if (!enable && intel_crtc->overlay) {
                 overlay = intel_crtc->overlay;
                 mutex_lock(&overlay->dev->struct_mutex);
-                intel_overlay_switch_off(overlay);
+                for (;;) {
+                        ret = intel_overlay_switch_off(overlay);
+                        if (ret == 0)
+                                break;
+
+                        ret = intel_overlay_recover_from_interrupt(overlay, 0);
+                        if (ret != 0) {
+                                /* overlay doesn't react anymore. Usually
+                                 * results in a black screen and an unkillable
+                                 * X server. */
+                                BUG();
+                                overlay->hw_wedged = HW_WEDGED;
+                                break;
+                        }
+                }
                 mutex_unlock(&overlay->dev->struct_mutex);
         }
         /* Let userspace switch the overlay on again. In most cases userspace
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5b503cb793ba..497240581c6a 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -127,8 +127,13 @@ struct intel_overlay {
         struct drm_i915_gem_object *reg_bo;
         void *virt_addr;
         /* flip handling */
-        int hw_wedged;
         uint32_t last_flip_req;
+        int hw_wedged;
+#define HW_WEDGED               1
+#define NEEDS_WAIT_FOR_FLIP     2
+#define RELEASE_OLD_VID         3
+#define SWITCH_OFF_STAGE_1      4
+#define SWITCH_OFF_STAGE_2      5
 };
 
 struct intel_crtc {
@@ -209,6 +214,8 @@ extern int intel_framebuffer_create(struct drm_device *dev,
 extern void intel_setup_overlay(struct drm_device *dev);
 extern void intel_cleanup_overlay(struct drm_device *dev);
 extern int intel_overlay_switch_off(struct intel_overlay *overlay);
+extern int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay,
+                                                int interruptible);
 extern int intel_overlay_put_image(struct drm_device *dev, void *data,
                                    struct drm_file *file_priv);
 extern int intel_overlay_attrs(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 85e07e4459ce..972d715245be 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -222,6 +222,9 @@ static int intel_overlay_on(struct intel_overlay *overlay)
 
         BUG_ON(overlay->active);
 
+        overlay->active = 1;
+        overlay->hw_wedged = NEEDS_WAIT_FOR_FLIP;
+
         BEGIN_LP_RING(6);
         OUT_RING(MI_FLUSH);
         OUT_RING(MI_NOOP);
@@ -231,15 +234,16 @@ static int intel_overlay_on(struct intel_overlay *overlay)
         OUT_RING(MI_NOOP);
         ADVANCE_LP_RING();
 
-        ret = i915_lp_ring_sync(dev);
-        if (ret != 0) {
-                DRM_ERROR("intel overlay: ring sync failed, hw likely wedged\n");
-                overlay->hw_wedged = 1;
-                return 0;
-        }
+        overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+        if (overlay->last_flip_req == 0)
+                return -ENOMEM;
 
-        overlay->active = 1;
+        ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
+        if (ret != 0)
+                return ret;
 
+        overlay->hw_wedged = 0;
+        overlay->last_flip_req = 0;
         return 0;
 }
 
@@ -283,7 +287,6 @@ static int intel_overlay_wait_flip(struct intel_overlay *overlay)
 
         if (overlay->last_flip_req != 0) {
                 ret = i915_do_wait_request(dev, overlay->last_flip_req, 0);
-
                 if (ret != 0)
                         return ret;
 
@@ -296,19 +299,24 @@ static int intel_overlay_wait_flip(struct intel_overlay *overlay)
         }
 
         /* synchronous slowpath */
+        overlay->hw_wedged = RELEASE_OLD_VID;
+
         BEGIN_LP_RING(2);
         OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
         OUT_RING(MI_NOOP);
         ADVANCE_LP_RING();
 
-        /* run in lockstep with the hw for easier testing */
-        ret = i915_lp_ring_sync(dev);
-        if (ret != 0) {
-                DRM_ERROR("intel overlay: ring sync failed, hw likely wedged\n");
-                overlay->hw_wedged = 1;
-        }
+        overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+        if (overlay->last_flip_req == 0)
+                return -ENOMEM;
 
-        return ret;
+        ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
+        if (ret != 0)
+                return ret;
+
+        overlay->hw_wedged = 0;
+        overlay->last_flip_req = 0;
+        return 0;
 }
 
 /* overlay needs to be disabled in OCMD reg */
@@ -329,6 +337,8 @@ static int intel_overlay_off(struct intel_overlay *overlay)
         flip_addr |= OFC_UPDATE;
 
         /* wait for overlay to go idle */
+        overlay->hw_wedged = SWITCH_OFF_STAGE_1;
+
         BEGIN_LP_RING(6);
         OUT_RING(MI_FLUSH);
         OUT_RING(MI_NOOP);
@@ -338,14 +348,17 @@ static int intel_overlay_off(struct intel_overlay *overlay)
         OUT_RING(MI_NOOP);
         ADVANCE_LP_RING();
 
-        ret = i915_lp_ring_sync(dev);
-        if (ret != 0) {
-                DRM_ERROR("intel overlay: ring sync failed, hw likely wedged\n");
-                overlay->hw_wedged = 1;
+        overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+        if (overlay->last_flip_req == 0)
+                return -ENOMEM;
+
+        ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
+        if (ret != 0)
                 return ret;
-        }
 
         /* turn overlay off */
+        overlay->hw_wedged = SWITCH_OFF_STAGE_2;
+
         BEGIN_LP_RING(6);
         OUT_RING(MI_FLUSH);
         OUT_RING(MI_NOOP);
@@ -355,18 +368,100 @@ static int intel_overlay_off(struct intel_overlay *overlay)
         OUT_RING(MI_NOOP);
         ADVANCE_LP_RING();
 
-        ret = i915_lp_ring_sync(dev);
-        if (ret != 0) {
-                DRM_ERROR("intel overlay: ring sync failed, hw likely wedged\n");
-                overlay->hw_wedged = 1;
+        overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+        if (overlay->last_flip_req == 0)
+                return -ENOMEM;
+
+        ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
+        if (ret != 0)
                 return ret;
-        }
 
         overlay->active = 0;
-
+        overlay->hw_wedged = 0;
+        overlay->last_flip_req = 0;
         return ret;
 }
 
+/* recover from an interruption due to a signal
+ * We have to be careful not to repeat work forever an make forward progess. */
+int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay,
+                                         int interruptible)
+{
+        struct drm_device *dev = overlay->dev;
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        struct drm_gem_object *obj;
+        u32 flip_addr;
+        int ret;
+        RING_LOCALS;
+
+        if (overlay->hw_wedged == HW_WEDGED)
+                return -EIO;
+
+        if (overlay->last_flip_req == 0) {
+                overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+                if (overlay->last_flip_req == 0)
+                        return -ENOMEM;
+        }
+
+        ret = i915_do_wait_request(dev, overlay->last_flip_req, interruptible);
+        if (ret != 0)
+                return ret;
+
+        switch (overlay->hw_wedged) {
+                case RELEASE_OLD_VID:
+                        obj = overlay->old_vid_bo->obj;
+                        i915_gem_object_unpin(obj);
+                        drm_gem_object_unreference(obj);
+                        overlay->old_vid_bo = NULL;
+                        break;
+                case SWITCH_OFF_STAGE_1:
+                        flip_addr = overlay->flip_addr;
+                        flip_addr |= OFC_UPDATE;
+
+                        overlay->hw_wedged = SWITCH_OFF_STAGE_2;
+
+                        BEGIN_LP_RING(6);
+                        OUT_RING(MI_FLUSH);
+                        OUT_RING(MI_NOOP);
+                        OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_OFF);
+                        OUT_RING(flip_addr);
+                        OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
+                        OUT_RING(MI_NOOP);
+                        ADVANCE_LP_RING();
+
+                        overlay->last_flip_req = i915_add_request(dev, NULL, 0);
+                        if (overlay->last_flip_req == 0)
+                                return -ENOMEM;
+
+                        ret = i915_do_wait_request(dev, overlay->last_flip_req,
+                                        interruptible);
+                        if (ret != 0)
+                                return ret;
+
+                case SWITCH_OFF_STAGE_2:
+                        printk("switch off 2\n");
+
+                        BUG_ON(!overlay->vid_bo);
+                        obj = overlay->vid_bo->obj;
+
+                        i915_gem_object_unpin(obj);
+                        drm_gem_object_unreference(obj);
+                        overlay->vid_bo = NULL;
+
+                        overlay->crtc->overlay = NULL;
+                        overlay->crtc = NULL;
+
+                        overlay->active = 0;
+                        break;
+                default:
+                        BUG_ON(overlay->hw_wedged != NEEDS_WAIT_FOR_FLIP);
+        }
+
+        overlay->hw_wedged = 0;
+        overlay->last_flip_req = 0;
+        return 0;
+}
+
 /* Wait for pending overlay flip and release old frame.
  * Needs to be called before the overlay register are changed
  * via intel_overlay_(un)map_regs_atomic */
@@ -375,13 +470,15 @@ static int intel_overlay_release_old_vid(struct intel_overlay *overlay)
         int ret;
         struct drm_gem_object *obj;
 
+        /* only wait if there is actually an old frame to release to
+         * guarantee forward progress */
+        if (!overlay->old_vid_bo)
+                return 0;
+
         ret = intel_overlay_wait_flip(overlay);
         if (ret != 0)
                 return ret;
 
-        if (!overlay->old_vid_bo)
-                return 0;
-
         obj = overlay->old_vid_bo->obj;
         i915_gem_object_unpin(obj);
         drm_gem_object_unreference(obj);
@@ -646,9 +743,6 @@ int intel_overlay_do_put_image(struct intel_overlay *overlay,
         BUG_ON(!mutex_is_locked(&dev->mode_config.mutex));
         BUG_ON(!overlay);
 
-        if (overlay->hw_wedged)
-                return -EBUSY;
-
         ret = intel_overlay_release_old_vid(overlay);
         if (ret != 0)
                 return ret;
@@ -761,6 +855,9 @@ int intel_overlay_switch_off(struct intel_overlay *overlay)
         intel_overlay_unmap_regs_atomic(overlay);
 
         ret = intel_overlay_off(overlay);
+        if (ret != 0)
+                return ret;
+
         /* never have the overlay hw on without showing a frame */
         BUG_ON(!overlay->vid_bo);
         obj = overlay->vid_bo->obj;
@@ -1002,6 +1099,12 @@ int intel_overlay_put_image(struct drm_device *dev, void *data,
         mutex_lock(&dev->mode_config.mutex);
         mutex_lock(&dev->struct_mutex);
 
+        if (overlay->hw_wedged) {
+                ret = intel_overlay_recover_from_interrupt(overlay, 1);
+                if (ret != 0)
+                        goto out_unlock;
+        }
+
         if (overlay->crtc != crtc) {
                 struct drm_display_mode *mode = &crtc->base.mode;
                 ret = intel_overlay_switch_off(overlay);