Hand merged.

drivers/isdn/i4l/isdn_concap.c

@@ -106,3 +106,39 @@ struct concap_proto * isdn_concap_new( int encap )
 	}
 	return NULL;
 }
+
+void isdn_x25_encap_changed(isdn_net_dev *p, isdn_net_ioctl_cfg *cfg)
+{
+	isdn_net_local *lp = &p->local;
+	struct concap_proto * cprot = p -> cprot;
+	unsigned long flags;
+	
+	/* delete old encapsulation protocol if present ... */
+	save_flags(flags);
+	cli(); /* avoid races with incoming events trying to
+		  call cprot->pops methods */
+	if( cprot && cprot -> pops )
+		cprot -> pops -> proto_del ( cprot );
+	p -> cprot = NULL;
+	lp -> dops = NULL;
+	restore_flags(flags);
+	/* ... ,  prepare for configuration of new one ... */
+	switch ( cfg -> p_encap ){
+	case ISDN_NET_ENCAP_X25IFACE:
+		lp -> dops = &isdn_concap_reliable_dl_dops;
+	}
+	/* ... and allocate new one ... */
+	p -> cprot = isdn_concap_new( cfg -> p_encap );
+	/* p -> cprot == NULL now if p_encap is not supported
+	   by means of the concap_proto mechanism */
+	/* the protocol is not configured yet; this will
+	   happen later when isdn_net_reset() is called */
+}
+
+int isdn_x25_setup_dev(isdn_net_dev *p)
+{
+	p->dev.type = ARPHRD_X25;	/* change ARP type */
+	p->dev.addr_len = 0;
+
+	return 0;
+}

drivers/isdn/i4l/isdn_concap.h

@@ -9,6 +9,27 @@
 
 extern struct concap_device_ops isdn_concap_reliable_dl_dops;
 extern struct concap_device_ops isdn_concap_demand_dial_dops;
-extern struct concap_proto * isdn_concap_new( int );
 
+struct concap_proto *isdn_concap_new(int);
 
+#ifdef CONFIG_ISDN_X25
+
+void isdn_x25_encap_changed(isdn_net_dev *p, isdn_net_ioctl_cfg *cfg);
+int  isdn_x25_setup_dev(isdn_net_dev *p);
+
+#else
+
+static inline void
+isdn_x25_encap_changed(isdn_net_dev *p, isdn_net_ioctl_cfg *cfg)
+{
+}
+
+static inline int 
+isdn_x25_setup_dev(isdn_net_dev *p)
+{
+	printk(KERN_WARNING "ISDN: SyncPPP support not configured\n");
+	return -EINVAL;
+}
+
+
+#endif

drivers/isdn/i4l/isdn_ppp.c

@@ -14,6 +14,7 @@
 #include <linux/smp_lock.h>
 #include <linux/poll.h>
 #include <linux/ppp-comp.h>
+#include <linux/if_arp.h>
 
 #include "isdn_common.h"
 #include "isdn_ppp.h"
@@ -2893,3 +2894,12 @@ static int isdn_ppp_set_compressor(struct ippp_struct *is, struct isdn_ppp_comp_
 	}
 	return -EINVAL;
 }
+
+int isdn_ppp_setup_dev(isdn_net_dev *p)
+{
+	p->dev.type = ARPHRD_PPP;	/* change ARP type */
+	p->dev.addr_len = 0;
+	p->dev.do_ioctl = isdn_ppp_dev_ioctl;
+
+	return 0;
+}

drivers/isdn/i4l/isdn_ppp.h

@@ -20,13 +20,27 @@ extern int isdn_ppp_free(isdn_net_local *);
 extern int isdn_ppp_bind(isdn_net_local *);
 extern int isdn_ppp_xmit(struct sk_buff *, struct net_device *);
 extern void isdn_ppp_receive(isdn_net_dev *, isdn_net_local *, struct sk_buff *);
-extern int isdn_ppp_dev_ioctl(struct net_device *, struct ifreq *, int);
 extern int isdn_ppp_dial_slave(char *);
 extern void isdn_ppp_wakeup_daemon(isdn_net_local *);
 
 extern int isdn_ppp_register_compressor(struct isdn_ppp_compressor *ipc);
 extern int isdn_ppp_unregister_compressor(struct isdn_ppp_compressor *ipc);
 
+#ifdef CONFIG_ISDN_PPP
+
+int isdn_ppp_setup_dev(isdn_net_dev *p);
+
+#else
+
+static inline int
+isdn_ppp_setup_dev(isdn_net_dev *p)
+{
+	printk(KERN_WARNING "ISDN: SyncPPP support not configured\n");
+	return -EINVAL;
+}
+
+#endif
+
 #define IPPP_OPEN	0x01
 #define IPPP_CONNECT	0x02
 #define IPPP_CLOSEWAIT	0x04