fixed NULL dereference problem in do_become_nonbusy() caused by async changes

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 237595540097c34fc2b4960246a4c304ef4a5658..d7e3939f80313de55e71c5b5911733151b62ea4d 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -537,7 +537,7 @@ static int do_trig_ioctl_mode0(comedi_device *dev,comedi_subdevice *s,comedi_tri
        int reading;
        int bufsz;
        int ret=0,i;
-       comedi_async *async = s->async;
+//     comedi_async *async = s->async;
 
        /* make sure channel/gain list isn't too long */
        if(user_trig->n_chan > s->len_chanlist){
@@ -579,12 +579,13 @@ static int do_trig_ioctl_mode0(comedi_device *dev,comedi_subdevice *s,comedi_tri
                goto cleanup;
        }
 
-       async->buf_int_ptr=0;
-       async->buf_int_count=0;
-       if(s->subdev_flags & SDF_READABLE){
-               async->buf_user_ptr=0;
-               async->buf_user_count=0;
-       }
+// this stuff isn't used in mode0
+//     async->buf_int_ptr=0;
+//     async->buf_int_count=0;
+//     if(s->subdev_flags & SDF_READABLE){
+//             async->buf_user_ptr=0;
+//             async->buf_user_count=0;
+//     }
 
        if(s->subdev_flags & SDF_WRITEABLE){
                if(s->subdev_flags & SDF_READABLE){
@@ -1655,10 +1656,13 @@ static void do_become_nonbusy(comedi_device *dev,comedi_subdevice *s)
                s->cur_trig.data=NULL;
        }
 
-       async->buf_user_ptr=0;
-       async->buf_int_ptr=0;
-       async->buf_user_count=0;
-       async->buf_int_count=0;
+       if(async)
+       {
+               async->buf_user_ptr=0;
+               async->buf_int_ptr=0;
+               async->buf_user_count=0;
+               async->buf_int_count=0;
+       }
 
        s->busy=NULL;
 }