OMAP: DSS2: Taal: add locks to taal_bl_update_status

taal_bl_update_status was missing locks to protect taal_data. This caused
a kernel crash randomly, as the code attempted to set the brightness while
the OMAP's DSI block was actually disabled.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/video/omap2/displays/panel-taal.c b/drivers/video/omap2/displays/panel-taal.c
index aaf5d308a046..d2e2ac7444e0 100644
--- a/drivers/video/omap2/displays/panel-taal.c
+++ b/drivers/video/omap2/displays/panel-taal.c
@@ -290,24 +290,26 @@ static int taal_bl_update_status(struct backlight_device *dev)
 
         dev_dbg(&dssdev->dev, "update brightness to %d\n", level);
 
+        mutex_lock(&td->lock);
+
         if (td->use_dsi_bl) {
                 if (td->enabled) {
                         dsi_bus_lock();
                         r = taal_dcs_write_1(DCS_BRIGHTNESS, level);
                         dsi_bus_unlock();
-                        if (r)
-                                return r;
+                } else {
+                        r = 0;
                 }
         } else {
                 if (!dssdev->set_backlight)
-                        return -EINVAL;
-
-                r = dssdev->set_backlight(dssdev, level);
-                if (r)
-                        return r;
+                        r = -EINVAL;
+                else
+                        r = dssdev->set_backlight(dssdev, level);
         }
 
-        return 0;
+        mutex_unlock(&td->lock);
+
+        return r;
 }
 
 static int taal_bl_get_intensity(struct backlight_device *dev)