[PATCH] isdn: work around excessive udelay()

As reported in http://bugzilla.kernel.org/show_bug.cgi?id=6970, ISDN can issue
excessively-long udelays, which triggers a build-time error on ARM.

This is very sucky of ISDN, but I doubt if anyone is going to suddenly fix it.
So change the macro to do the microsecond counting itself.

Cc: <tch@wpkg.org>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/isdn/hisax/hisax.h

@@ -1316,7 +1316,18 @@ void dlogframe(struct IsdnCardState *cs, struct sk_buff *skb, int dir);
 void iecpy(u_char * dest, u_char * iestart, int ieoffset);
 #endif	/* __KERNEL__ */
 
-#define HZDELAY(jiffs) {int tout = jiffs; while (tout--) udelay(1000000/HZ);}
+/*
+ * Busywait delay for `jiffs' jiffies
+ */
+#define HZDELAY(jiffs) do {					\
+		int tout = jiffs;				\
+								\
+		while (tout--) {				\
+			int loops = USEC_PER_SEC / HZ;		\
+			while (loops--)				\
+				udelay(1);			\
+		}						\
+	} while (0)
 
 int ll_run(struct IsdnCardState *cs, int addfeatures);
 int CallcNew(void);