OMAPDSS: fix WARN_ON in 'alpha_blending_enabled' sysfs file

The code handling 'alpha_blending_enabled' sysfs file contains WARN_ONs
in case the feature is not supported on the current platform. Even
though only root can write to the file, anyone can read it, thus causing
the kernel to get tainted and printing an ugly warning.

Instead of having WARN_ONs, return a proper error if the feature is not
supported.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>

diff --git a/drivers/video/omap2/dss/manager-sysfs.c b/drivers/video/omap2/dss/manager-sysfs.c
index de7e7b5b1b7c05d7b3371edd8d9e1205abfdeec5..37b59fe28dc8ad77dc49daa2fa63127b3fc7450f 100644 (file)
--- a/drivers/video/omap2/dss/manager-sysfs.c
+++ b/drivers/video/omap2/dss/manager-sysfs.c
@@ -285,9 +285,10 @@ static ssize_t manager_alpha_blending_enabled_show(
 {
        struct omap_overlay_manager_info info;
 
-       mgr->get_manager_info(mgr, &info);
+       if(!dss_has_feature(FEAT_ALPHA_FIXED_ZORDER))
+               return -ENODEV;
 
-       WARN_ON(!dss_has_feature(FEAT_ALPHA_FIXED_ZORDER));
+       mgr->get_manager_info(mgr, &info);
 
        return snprintf(buf, PAGE_SIZE, "%d\n",
                info.partial_alpha_enabled);
@@ -301,7 +302,8 @@ static ssize_t manager_alpha_blending_enabled_store(
        bool enable;
        int r;
 
-       WARN_ON(!dss_has_feature(FEAT_ALPHA_FIXED_ZORDER));
+       if(!dss_has_feature(FEAT_ALPHA_FIXED_ZORDER))
+               return -ENODEV;
 
        r = strtobool(buf, &enable);
        if (r)