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>

diff --git a/drivers/video/omap2/displays/panel-taal.c b/drivers/video/omap2/displays/panel-taal.c
index aaf5d30..d2e2ac7 100644 (file)
--- 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)