Do not set IFF_DEBUG directly from the driver.

MFC after:	1 month.

2 files changed, 13 insertions, 7 deletions

diff --git a/sys/dev/ctau/ctddk.h b/sys/dev/ctau/ctddk.h
index 9962090..be0a092 100644
--- a/sys/dev/ctau/ctddk.h
+++ b/sys/dev/ctau/ctddk.h
@@ -412,6 +412,7 @@ typedef struct _ct_chan_t {
 	void *attach [NBUF];		/* system dependent data per buffer */
 	void *sys;			/* system dependent data per channel */
 	int debug;
+	int debug_shadow;
 
 	int e1_first_int;
 	unsigned char *sccrx, *scctx;  /* pointers to SCC rx and tx buffers */
diff --git a/sys/dev/ctau/if_ct.c b/sys/dev/ctau/if_ct.c
index 25e927a..f2d876d 100644
--- a/sys/dev/ctau/if_ct.c
+++ b/sys/dev/ctau/if_ct.c
@@ -949,8 +949,8 @@ static int ct_sioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
 
 	if (! (ifp->if_flags & IFF_DEBUG))
 		d->chan->debug = 0;
-	else if (! d->chan->debug)
-		d->chan->debug = 1;
+	else
+		d->chan->debug = d->chan->debug_shadow;
 
 	switch (cmd) {
 	default:	   CT_DEBUG2 (d, ("ioctl 0x%lx\n", cmd)); return 0;
@@ -1529,12 +1529,17 @@ static int ct_ioctl (struct cdev *dev, u_long cmd, caddr_t data, int flag, struc
 		error = priv_check (td, PRIV_DRIVER);
 		if (error)
 			return error;
-		c->debug = *(int*)data;
 #ifndef	NETGRAPH
-		if (d->chan->debug)
-			d->ifp->if_flags |= IFF_DEBUG;
-		else
-			d->ifp->if_flags &= (~IFF_DEBUG);
+		/*
+		 * The debug_shadow is always greater than zero for logic 
+		 * simplicity.  For switching debug off the IFF_DEBUG is
+		 * responsible.
+		 */
+		c->debug_shadow = (*(int*)data) ? (*(int*)data) : 1;
+		if (d->ifp->if_flags & IFF_DEBUG)
+			c->debug = c->debug_shadow;
+#else
+		c->debug = *(int*)data;
 #endif
 		return 0;