3 files changed, 43 insertions, 4 deletions

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 528429252f0f..02e52d543e4b 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -241,6 +241,8 @@ struct ast_fbdev {
         void *sysram;
         int size;
         struct ttm_bo_kmap_obj mapping;
+        int x1, y1, x2, y2; /* dirty rect */
+        spinlock_t dirty_lock;
 };
 
 #define to_ast_crtc(x) container_of(x, struct ast_crtc, base)
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
index 34931fe7d2c5..fbc0823cfa18 100644
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ b/drivers/gpu/drm/ast/ast_fb.c
@@ -53,16 +53,52 @@ static void ast_dirty_update(struct ast_fbdev *afbdev,
         int bpp = (afbdev->afb.base.bits_per_pixel + 7)/8;
         int ret;
         bool unmap = false;
+        bool store_for_later = false;
+        int x2, y2;
+        unsigned long flags;
 
         obj = afbdev->afb.obj;
         bo = gem_to_ast_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 = ast_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) {
@@ -72,10 +108,10 @@ static void ast_dirty_update(struct ast_fbdev *afbdev,
                 }
                 unmap = true;
         }
-        for (i = y; i < y + height; i++) {
+        for (i = y; i <= y2; i++) {
                 /* assume equal stride for now */
                 src_offset = dst_offset = i * afbdev->afb.base.pitches[0] + (x * bpp);
-                memcpy_toio(bo->kmap.virtual + src_offset, afbdev->sysram + src_offset, width * bpp);
+                memcpy_toio(bo->kmap.virtual + src_offset, afbdev->sysram + src_offset, (x2 - x + 1) * bpp);
 
         }
         if (unmap)
@@ -292,6 +328,7 @@ int ast_fbdev_init(struct drm_device *dev)
 
         ast->fbdev = afbdev;
         afbdev->helper.funcs = &ast_fb_helper_funcs;
+        spin_lock_init(&afbdev->dirty_lock);
         ret = drm_fb_helper_init(dev, &afbdev->helper,
                                  1, 1);
         if (ret) {
diff --git a/drivers/gpu/drm/ast/ast_ttm.c b/drivers/gpu/drm/ast/ast_ttm.c
index 3602731a6112..09da3393c527 100644
--- a/drivers/gpu/drm/ast/ast_ttm.c
+++ b/drivers/gpu/drm/ast/ast_ttm.c
@@ -316,7 +316,7 @@ int ast_bo_reserve(struct ast_bo *bo, bool no_wait)
 
         ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, 0);
         if (ret) {
-                if (ret != -ERESTARTSYS)
+                if (ret != -ERESTARTSYS && ret != -EBUSY)
                         DRM_ERROR("reserve failed %p\n", bo);
                 return ret;
         }