Only set SRF_RT subdevice flag if comedi_switch_to_rt(dev) succeeds.

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 181cd0320c2cc38c21ef4dba206af2dbc0e57e8b..e182e509951b5cd847d9074f9c963273742c301f 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -1051,8 +1051,8 @@ static int do_cmd_ioctl(comedi_device * dev, void *arg, void *file)
 
 #ifdef CONFIG_COMEDI_RT
        if (async->cmd.flags & TRIG_RT) {
-               comedi_switch_to_rt(dev);
-               comedi_set_subdevice_runflags(s, SRF_RT, SRF_RT);
+               if (comedi_switch_to_rt(dev) == 0)
+                       comedi_set_subdevice_runflags(s, SRF_RT, SRF_RT);
        }
 #endif