OMAP: DSS2: OMAPFB: Add some locking debug checks

Trigger WARN_ON() messages from various places in the code in case the
memory region is not currently locked.

Signed-off-by: Ville Syrjälä <ville.syrjala@nokia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

4 files changed, 13 insertions, 0 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 7975a99c33f9..d1f56d37405f 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -222,6 +222,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
         rg = ofbi->region;
 
         down_write_nested(&rg->lock, rg->id);
+        atomic_inc(&rg->lock_count);
 
         if (atomic_read(&rg->map_count)) {
                 r = -EBUSY;
@@ -252,6 +253,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
         }
 
  out:
+        atomic_dec(&rg->lock_count);
         up_write(&rg->lock);
 
         return r;
diff --git a/drivers/video/omap2/omapfb/omapfb-main.c b/drivers/video/omap2/omapfb/omapfb-main.c
index a3f72ba79958..a545e8d4817f 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -668,6 +668,8 @@ int check_fb_var(struct fb_info *fbi, struct fb_var_screeninfo *var)
 
         DBG("check_fb_var %d\n", ofbi->id);
 
+        WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
         r = fb_mode_to_dss_mode(var, &mode);
         if (r) {
                 DBG("cannot convert var to omap dss mode\n");
@@ -873,6 +875,8 @@ int omapfb_setup_overlay(struct fb_info *fbi, struct omap_overlay *ovl,
         int rotation = var->rotate;
         int i;
 
+        WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
         for (i = 0; i < ofbi->num_overlays; i++) {
                 if (ovl != ofbi->overlays[i])
                         continue;
@@ -966,6 +970,8 @@ int omapfb_apply_changes(struct fb_info *fbi, int init)
                 fill_fb(fbi);
 #endif
 
+        WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
         for (i = 0; i < ofbi->num_overlays; i++) {
                 ovl = ofbi->overlays[i];
 
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index 1e714bb48d39..51c13c366bf3 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -453,6 +453,7 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
         rg = ofbi->region;
 
         down_write_nested(&rg->lock, rg->id);
+        atomic_inc(&rg->lock_count);
 
         if (atomic_read(&rg->map_count)) {
                 r = -EBUSY;
@@ -484,6 +485,7 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
 
         r = count;
 out:
+        atomic_dec(&rg->lock_count);
         up_write(&rg->lock);
 
         unlock_fb_info(fbi);
diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 676b55d98941..1305fc9880ba 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -56,6 +56,7 @@ struct omapfb2_mem_region {
         bool            map;            /* kernel mapped by the driver */
         atomic_t        map_count;
         struct rw_semaphore lock;
+        atomic_t        lock_count;
 };
 
 /* appended to fb_info */
@@ -166,11 +167,13 @@ static inline struct omapfb2_mem_region *
 omapfb_get_mem_region(struct omapfb2_mem_region *rg)
 {
         down_read_nested(&rg->lock, rg->id);
+        atomic_inc(&rg->lock_count);
         return rg;
 }
 
 static inline void omapfb_put_mem_region(struct omapfb2_mem_region *rg)
 {
+        atomic_dec(&rg->lock_count);
         up_read(&rg->lock);
 }