3 files changed, 36 insertions, 13 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 3a10146dc120..7975a99c33f9 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -55,7 +55,7 @@ static struct omapfb2_mem_region *get_mem_region(struct omapfb_info *ofbi,
         if (mem_idx >= fbdev->num_fbs)
                 return NULL;
 
-        return omapfb_get_mem_region(&fbdev->regions[mem_idx]);
+        return &fbdev->regions[mem_idx];
 }
 
 static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
@@ -77,20 +77,30 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
         /* XXX uses only the first overlay */
         ovl = ofbi->overlays[0];
 
-        old_rg = omapfb_get_mem_region(ofbi->region);
+        old_rg = ofbi->region;
         new_rg = get_mem_region(ofbi, pi->mem_idx);
         if (!new_rg) {
                 r = -EINVAL;
-                goto put_old;
+                goto out;
         }
 
+        /* Take the locks in a specific order to keep lockdep happy */
+        if (old_rg->id < new_rg->id) {
+                omapfb_get_mem_region(old_rg);
+                omapfb_get_mem_region(new_rg);
+        } else if (new_rg->id < old_rg->id) {
+                omapfb_get_mem_region(new_rg);
+                omapfb_get_mem_region(old_rg);
+        } else
+                omapfb_get_mem_region(old_rg);
+
         if (pi->enabled && !new_rg->size) {
                 /*
                  * This plane's memory was freed, can't enable it
                  * until it's reallocated.
                  */
                 r = -EINVAL;
-                goto put_new;
+                goto put_mem;
         }
 
         ovl->get_overlay_info(ovl, &old_info);
@@ -135,8 +145,15 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
         if (ovl->manager)
                 ovl->manager->apply(ovl->manager);
 
-        omapfb_put_mem_region(new_rg);
-        omapfb_put_mem_region(old_rg);
+        /* Release the locks in a specific order to keep lockdep happy */
+        if (old_rg->id > new_rg->id) {
+                omapfb_put_mem_region(old_rg);
+                omapfb_put_mem_region(new_rg);
+        } else if (new_rg->id > old_rg->id) {
+                omapfb_put_mem_region(new_rg);
+                omapfb_put_mem_region(old_rg);
+        } else
+                omapfb_put_mem_region(old_rg);
 
         return 0;
 
@@ -147,10 +164,16 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
         }
 
         ovl->set_overlay_info(ovl, &old_info);
- put_new:
-        omapfb_put_mem_region(new_rg);
- put_old:
-        omapfb_put_mem_region(old_rg);
+ put_mem:
+        /* Release the locks in a specific order to keep lockdep happy */
+        if (old_rg->id > new_rg->id) {
+                omapfb_put_mem_region(old_rg);
+                omapfb_put_mem_region(new_rg);
+        } else if (new_rg->id > old_rg->id) {
+                omapfb_put_mem_region(new_rg);
+                omapfb_put_mem_region(old_rg);
+        } else
+                omapfb_put_mem_region(old_rg);
  out:
         dev_err(fbdev->dev, "setup_plane failed\n");
 
@@ -198,7 +221,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 
         rg = ofbi->region;
 
-        down_write(&rg->lock);
+        down_write_nested(&rg->lock, rg->id);
 
         if (atomic_read(&rg->map_count)) {
                 r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index 724b760404f2..1e714bb48d39 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -452,7 +452,7 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
 
         rg = ofbi->region;
 
-        down_write(&rg->lock);
+        down_write_nested(&rg->lock, rg->id);
 
         if (atomic_read(&rg->map_count)) {
                 r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 195a760eef54..676b55d98941 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -165,7 +165,7 @@ static inline int omapfb_overlay_enable(struct omap_overlay *ovl,
 static inline struct omapfb2_mem_region *
 omapfb_get_mem_region(struct omapfb2_mem_region *rg)
 {
-        down_read(&rg->lock);
+        down_read_nested(&rg->lock, rg->id);
         return rg;
 }