OMAP: DSS2: OMAPFB: Add locking for memory regions

Add locking to the memory regions to make sure the memory region size
won't be changed while some other piece of code is performing some
checks or setup based on that information.

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

1 files changed, 35 insertions, 2 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index dea1aa46a7d..74c11b24310 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -49,6 +49,7 @@ static ssize_t store_rotate_type(struct device *dev,
 {
 	struct fb_info *fbi = dev_get_drvdata(dev);
 	struct omapfb_info *ofbi = FB2OFB(fbi);
+	struct omapfb2_mem_region *rg;
 	enum omap_dss_rotation_type rot_type;
 	int r;
 
@@ -64,9 +65,11 @@ static ssize_t store_rotate_type(struct device *dev,
 	if (rot_type == ofbi->rotation_type)
 		goto out;
 
-	if (ofbi->region->size) {
+	rg = omapfb_get_mem_region(ofbi->region);
+
+	if (rg->size) {
 		r = -EBUSY;
-		goto out;
+		goto put_region;
 	}
 
 	ofbi->rotation_type = rot_type;
@@ -75,6 +78,8 @@ static ssize_t store_rotate_type(struct device *dev,
 	 * Since the VRAM for this FB is not allocated at the moment we don't
 	 * need to do any further parameter checking at this point.
 	 */
+put_region:
+	omapfb_put_mem_region(rg);
 out:
 	unlock_fb_info(fbi);
 
@@ -111,6 +116,8 @@ static ssize_t store_mirror(struct device *dev,
 
 	ofbi->mirror = mirror;
 
+	omapfb_get_mem_region(ofbi->region);
+
 	memcpy(&new_var, &fbi->var, sizeof(new_var));
 	r = check_fb_var(fbi, &new_var);
 	if (r)
@@ -125,6 +132,8 @@ static ssize_t store_mirror(struct device *dev,
 
 	r = count;
 out:
+	omapfb_put_mem_region(ofbi->region);
+
 	unlock_fb_info(fbi);
 
 	return r;
@@ -263,11 +272,15 @@ static ssize_t store_overlays(struct device *dev, struct device_attribute *attr,
 
 		DBG("detaching %d\n", ofbi->overlays[i]->id);
 
+		omapfb_get_mem_region(ofbi->region);
+
 		omapfb_overlay_enable(ovl, 0);
 
 		if (ovl->manager)
 			ovl->manager->apply(ovl->manager);
 
+		omapfb_put_mem_region(ofbi->region);
+
 		for (t = i + 1; t < ofbi->num_overlays; t++) {
 			ofbi->rotation[t-1] = ofbi->rotation[t];
 			ofbi->overlays[t-1] = ofbi->overlays[t];
@@ -300,7 +313,12 @@ static ssize_t store_overlays(struct device *dev, struct device_attribute *attr,
 	}
 
 	if (added) {
+		omapfb_get_mem_region(ofbi->region);
+
 		r = omapfb_apply_changes(fbi, 0);
+
+		omapfb_put_mem_region(ofbi->region);
+
 		if (r)
 			goto out;
 	}
@@ -388,7 +406,12 @@ static ssize_t store_overlays_rotate(struct device *dev,
 		for (i = 0; i < num_ovls; ++i)
 			ofbi->rotation[i] = rotation[i];
 
+		omapfb_get_mem_region(ofbi->region);
+
 		r = omapfb_apply_changes(fbi, 0);
+
+		omapfb_put_mem_region(ofbi->region);
+
 		if (r)
 			goto out;
 
@@ -429,6 +452,14 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
 
 	rg = ofbi->region;
 
+	/* FIXME probably should be a rwsem ... */
+	mutex_lock(&rg->mtx);
+	while (rg->ref) {
+		mutex_unlock(&rg->mtx);
+		schedule();
+		mutex_lock(&rg->mtx);
+	}
+
 	if (atomic_read(&rg->map_count)) {
 		r = -EBUSY;
 		goto out;
@@ -459,6 +490,8 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
 
 	r = count;
 out:
+	mutex_unlock(&rg->mtx);
+
 	unlock_fb_info(fbi);
 
 	return r;