OMAP: DSS2: Check if display supports update mode changes

Check whether the display actually has the set_update_mode() function
before calling it. Only the sysfs codepath was broken, the omapfb ioctl
had the necessary protection.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/video/omap2/dss/display.c b/drivers/video/omap2/dss/display.c
index ef8c8529dda2..480aeaa5f39c 100644
--- a/drivers/video/omap2/dss/display.c
+++ b/drivers/video/omap2/dss/display.c
@@ -82,6 +82,9 @@ static ssize_t display_upd_mode_store(struct device *dev,
         int val, r;
         enum omap_dss_update_mode mode;
 
+        if (!dssdev->driver->set_update_mode)
+                return -EINVAL;
+
         val = simple_strtoul(buf, NULL, 10);
 
         switch (val) {