1 files changed, 37 insertions, 1 deletions

diff --git a/drivers/gpu/drm/cirrus/cirrus_fbdev.c b/drivers/gpu/drm/cirrus/cirrus_fbdev.c
index e25afccaf85b..3541b567bbd8 100644
--- a/drivers/gpu/drm/cirrus/cirrus_fbdev.c
+++ b/drivers/gpu/drm/cirrus/cirrus_fbdev.c
@@ -27,16 +27,51 @@ static void cirrus_dirty_update(struct cirrus_fbdev *afbdev,
         int bpp = (afbdev->gfb.base.bits_per_pixel + 7)/8;
         int ret;
         bool unmap = false;
+        bool store_for_later = false;
+        int x2, y2;
+        unsigned long flags;
 
         obj = afbdev->gfb.obj;
         bo = gem_to_cirrus_bo(obj);
 
+        /*
+         * try and reserve the BO, if we fail with busy
+         * then the BO is being moved and we should
+         * store up the damage until later.
+         */
         ret = cirrus_bo_reserve(bo, true);
         if (ret) {
-                DRM_ERROR("failed to reserve fb bo\n");
+                if (ret != -EBUSY)
+                        return;
+                store_for_later = true;
+        }
+
+        x2 = x + width - 1;
+        y2 = y + height - 1;
+        spin_lock_irqsave(&afbdev->dirty_lock, flags);
+
+        if (afbdev->y1 < y)
+                y = afbdev->y1;
+        if (afbdev->y2 > y2)
+                y2 = afbdev->y2;
+        if (afbdev->x1 < x)
+                x = afbdev->x1;
+        if (afbdev->x2 > x2)
+                x2 = afbdev->x2;
+
+        if (store_for_later) {
+                afbdev->x1 = x;
+                afbdev->x2 = x2;
+                afbdev->y1 = y;
+                afbdev->y2 = y2;
+                spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
                 return;
         }
 
+        afbdev->x1 = afbdev->y1 = INT_MAX;
+        afbdev->x2 = afbdev->y2 = 0;
+        spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
+
         if (!bo->kmap.virtual) {
                 ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
                 if (ret) {
@@ -268,6 +303,7 @@ int cirrus_fbdev_init(struct cirrus_device *cdev)
 
         cdev->mode_info.gfbdev = gfbdev;
         gfbdev->helper.funcs = &cirrus_fb_helper_funcs;
+        spin_lock_init(&gfbdev->dirty_lock);
 
         ret = drm_fb_helper_init(cdev->dev, &gfbdev->helper,
                                  cdev->num_crtc, CIRRUSFB_CONN_LIMIT);