diff --git a/sys/arm/mv/gpio.c b/sys/arm/mv/gpio.c
--- a/sys/arm/mv/gpio.c
+++ b/sys/arm/mv/gpio.c
@@ -529,9 +529,6 @@
 
 	MV_GPIO_ASSERT_LOCKED();
 
-#ifdef INTR_SOLO
-	isrc.isrc_filter = NULL;
-#endif
 	isrc.isrc_event = sc->gpio_events[pin];
 
 	if (isrc.isrc_event == NULL ||
diff --git a/sys/kern/subr_intr.c b/sys/kern/subr_intr.c
--- a/sys/kern/subr_intr.c
+++ b/sys/kern/subr_intr.c
@@ -98,7 +98,7 @@
 
 /* Root interrupt controller stuff. */
 device_t intr_irq_root_dev;
-static intr_irq_filter_t *irq_root_filter;
+static driver_filter_t *irq_root_filter;
 static void *irq_root_arg;
 static u_int irq_root_ipicount;
 
@@ -397,15 +397,6 @@
 
 	isrc_increment_count(isrc);
 
-#ifdef INTR_SOLO
-	if (isrc->isrc_filter != NULL) {
-		int error;
-		error = isrc->isrc_filter(isrc->isrc_arg, tf);
-		PIC_POST_FILTER(isrc->isrc_dev, isrc);
-		if (error == FILTER_HANDLED)
-			return (0);
-	} else
-#endif
 	if (intr_event_handle(isrc->isrc_event, tf) == 0)
 		return (0);
 
@@ -573,37 +564,6 @@
 }
 #endif
 
-#ifdef INTR_SOLO
-/*
- *  Setup filter into interrupt source.
- */
-static int
-iscr_setup_filter(struct intr_irqsrc *isrc, const char *name,
-    intr_irq_filter_t *filter, void *arg, void **cookiep)
-{
-
-	if (filter == NULL)
-		return (EINVAL);
-
-	mtx_lock(&isrc_table_lock);
-	/*
-	 * Make sure that we do not mix the two ways
-	 * how we handle interrupt sources.
-	 */
-	if (isrc->isrc_filter != NULL || isrc->isrc_event != NULL) {
-		mtx_unlock(&isrc_table_lock);
-		return (EBUSY);
-	}
-	isrc->isrc_filter = filter;
-	isrc->isrc_arg = arg;
-	isrc_update_name(isrc, name);
-	mtx_unlock(&isrc_table_lock);
-
-	*cookiep = isrc;
-	return (0);
-}
-#endif
-
 /*
  *  Interrupt source pre_ithread method for MI interrupt framework.
  */
@@ -696,23 +656,15 @@
 		return (error);
 
 	mtx_lock(&isrc_table_lock);
-	/*
-	 * Make sure that we do not mix the two ways
-	 * how we handle interrupt sources. Let contested event wins.
-	 */
-#ifdef INTR_SOLO
-	if (isrc->isrc_filter != NULL || isrc->isrc_event != NULL) {
-#else
-	if (isrc->isrc_event != NULL) {
-#endif
-		mtx_unlock(&isrc_table_lock);
-		intr_event_destroy(ie);
-		return (isrc->isrc_event != NULL ? EBUSY : 0);
-	}
-	isrc->isrc_event = ie;
+	if (isrc->isrc_event == NULL) {
+		/* We may or may not have entered a race and won. */
+		isrc->isrc_event = ie;
+		ie = NULL;
+	} /* else {
+	** We entered a race and lost.  An event was successfully added. } */
 	mtx_unlock(&isrc_table_lock);
 
-	return (0);
+	return (intr_event_destroy(ie));
 }
 #ifdef notyet
 /*
@@ -893,7 +845,7 @@
  *     an interrupts property and thus no explicit interrupt parent."
  */
 int
-intr_pic_claim_root(device_t dev, intptr_t xref, intr_irq_filter_t *filter,
+intr_pic_claim_root(device_t dev, intptr_t xref, driver_filter_t *filter,
     void *arg, u_int ipicount)
 {
 	struct intr_pic *pic;
@@ -1096,34 +1048,8 @@
 	data = rman_get_virtual(res);
 	name = device_get_nameunit(dev);
 
-#ifdef INTR_SOLO
-	/*
-	 * Standard handling is done through MI interrupt framework. However,
-	 * some interrupts could request solely own special handling. This
-	 * non standard handling can be used for interrupt controllers without
-	 * handler (filter only), so in case that interrupt controllers are
-	 * chained, MI interrupt framework is called only in leaf controller.
-	 *
-	 * Note that root interrupt controller routine is served as well,
-	 * however in intr_irq_handler(), i.e. main system dispatch routine.
-	 */
-	if (flags & INTR_SOLO && hand != NULL) {
-		debugf("irq %u cannot solo on %s\n", irq, name);
-		return (EINVAL);
-	}
-
-	if (flags & INTR_SOLO) {
-		error = iscr_setup_filter(isrc, name, (intr_irq_filter_t *)filt,
-		    arg, cookiep);
-		debugf("irq %u setup filter error %d on %s\n", isrc->isrc_irq, error,
-		    name);
-	} else
-#endif
-		{
-		error = isrc_add_handler(isrc, name, filt, hand, arg, flags,
-		    cookiep);
-		debugf("irq %u add handler error %d on %s\n", isrc->isrc_irq, error, name);
-	}
+	error = isrc_add_handler(isrc, name, filt, hand, arg, flags, cookiep);
+	debugf("irq %u add handler error %d on %s\n", isrc->isrc_irq, error, name);
 	if (error != 0)
 		return (error);
 
@@ -1158,22 +1084,6 @@
 
 	data = rman_get_virtual(res);
 
-#ifdef INTR_SOLO
-	if (isrc->isrc_filter != NULL) {
-		if (isrc != cookie)
-			return (EINVAL);
-
-		mtx_lock(&isrc_table_lock);
-		isrc->isrc_filter = NULL;
-		isrc->isrc_arg = NULL;
-		isrc->isrc_handlers = 0;
-		PIC_DISABLE_INTR(isrc->isrc_dev, isrc);
-		PIC_TEARDOWN_INTR(isrc->isrc_dev, isrc, res, data);
-		isrc_update_name(isrc, NULL);
-		mtx_unlock(&isrc_table_lock);
-		return (0);
-	}
-#endif
 	if (isrc != intr_handler_source(cookie))
 		return (EINVAL);
 
@@ -1205,17 +1115,7 @@
 	isrc = intr_map_get_isrc(res_id);
 	if (isrc == NULL || isrc->isrc_handlers == 0)
 		return (EINVAL);
-#ifdef INTR_SOLO
-	if (isrc->isrc_filter != NULL) {
-		if (isrc != cookie)
-			return (EINVAL);
 
-		mtx_lock(&isrc_table_lock);
-		isrc_update_name(isrc, descr);
-		mtx_unlock(&isrc_table_lock);
-		return (0);
-	}
-#endif
 	error = intr_event_describe_handler(isrc->isrc_event, cookie, descr);
 	if (error == 0) {
 		mtx_lock(&isrc_table_lock);
@@ -1239,10 +1139,6 @@
 	isrc = intr_map_get_isrc(res_id);
 	if (isrc == NULL || isrc->isrc_handlers == 0)
 		return (EINVAL);
-#ifdef INTR_SOLO
-	if (isrc->isrc_filter != NULL)
-		return (intr_isrc_assign_cpu(isrc, cpu));
-#endif
 	return (intr_event_bind(isrc->isrc_event, cpu));
 }
 
diff --git a/sys/sys/intr.h b/sys/sys/intr.h
--- a/sys/sys/intr.h
+++ b/sys/sys/intr.h
@@ -71,12 +71,6 @@
 	interrupt_t		*isrc;
 };
 
-#ifdef notyet
-#define	INTR_SOLO	INTR_MD1
-typedef int intr_irq_filter_t(void *arg, struct trapframe *tf);
-#else
-typedef int intr_irq_filter_t(void *arg);
-#endif
 typedef int intr_child_irq_filter_t(void *arg, uintptr_t irq);
 
 #define INTR_ISRC_NAMELEN	(MAXCOMLEN + 1)
@@ -98,10 +92,6 @@
 	u_long *		isrc_count;
 	u_int			isrc_handlers;
 	struct intr_event *	isrc_event;
-#ifdef INTR_SOLO
-	intr_irq_filter_t *	isrc_filter;
-	void *			isrc_arg;
-#endif
 	/* Used by MSI interrupts to store the iommu details */
 	void *			isrc_iommu;
 };
@@ -120,7 +110,7 @@
 
 struct intr_pic *intr_pic_register(device_t, intptr_t);
 int intr_pic_deregister(device_t, intptr_t);
-int intr_pic_claim_root(device_t, intptr_t, intr_irq_filter_t *, void *, u_int);
+int intr_pic_claim_root(device_t, intptr_t, driver_filter_t *, void *, u_int);
 int intr_pic_add_handler(device_t, struct intr_pic *,
     intr_child_irq_filter_t *, void *, uintptr_t, uintptr_t);
 bool intr_is_per_cpu(struct resource *);