327 	 * Dtc = (c - t)  in host1x_syncpt_is_expired()
331 	 *	A) .....c..t..f.....	Dtf < Dtc	need to wait  in host1x_syncpt_is_expired()
332 	 *	B) .....c.....f..t..	Dtf > Dtc	expired  in host1x_syncpt_is_expired()
333 	 *	C) ..t..c.....f.....	Dtf > Dtc	expired	   (Dct very large)  in host1x_syncpt_is_expired()
336 	 *  Any case where t==c: always expired (for any f).	Dtf >= Dtc (because Dtc==0)  in host1x_syncpt_is_expired()
337 	 *  Any case where t==f!=c: always wait.		Dtf <  Dtc (because Dtf==0,  in host1x_syncpt_is_expired()
338 	 *							Dtc!=0)  in host1x_syncpt_is_expired()
342 	 *	A) .....t..f..c.....	Dtf < Dtc	need to wait  in host1x_syncpt_is_expired()
343 	 *	A) .....f..c..t.....	Dtf < Dtc	need to wait  in host1x_syncpt_is_expired()
344 	 *	A) .....f..t..c.....	Dtf > Dtc	expired  in host1x_syncpt_is_expired()
347 	 *	   Dtf >= Dtc implies EXPIRED	(return true)  in host1x_syncpt_is_expired()
348 	 *	   Dtf <  Dtc implies WAIT	(return false)  in host1x_syncpt_is_expired()