From a2f51f57d195d45982aebd43255c063c65cf151c Mon Sep 17 00:00:00 2001
From: Andriy Gapon <avg@FreeBSD.org>
Date: Thu, 8 Sep 2016 12:27:34 +0000
Subject: [PATCH] intpm: better clean up resources after a failed attachment

bus_generic_detach() fails when called from attach method
thus preventing further clean up actions.

MFC after:	1 week
---
 sys/dev/intpm/intpm.c | 40 ++++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/sys/dev/intpm/intpm.c b/sys/dev/intpm/intpm.c
index c520d8927fb..3a5054ff1a6 100644
--- a/sys/dev/intpm/intpm.c
+++ b/sys/dev/intpm/intpm.c
@@ -199,6 +199,23 @@ sb8xx_attach(device_t dev)
 	return (0);
 }
 
+static void
+intsmb_release_resources(device_t dev)
+{
+	struct intsmb_softc *sc = device_get_softc(dev);
+
+	if (sc->smbus)
+		device_delete_child(dev, sc->smbus);
+	if (sc->irq_hand)
+		bus_teardown_intr(dev, sc->irq_res, sc->irq_hand);
+	if (sc->irq_res)
+		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
+	if (sc->io_res)
+		bus_release_resource(dev, SYS_RES_IOPORT, sc->io_rid,
+		    sc->io_res);
+	mtx_destroy(&sc->lock);
+}
+
 static int
 intsmb_attach(device_t dev)
 {
@@ -311,12 +328,15 @@ no_intr:
 	sc->isbusy = 0;
 	sc->smbus = device_add_child(dev, "smbus", -1);
 	if (sc->smbus == NULL) {
+		device_printf(dev, "failed to add smbus child\n");
 		error = ENXIO;
 		goto fail;
 	}
 	error = device_probe_and_attach(sc->smbus);
-	if (error)
+	if (error) {
+		device_printf(dev, "failed to probe+attach smbus child\n");
 		goto fail;
+	}
 
 #ifdef ENABLE_ALART
 	/* Enable Arart */
@@ -325,30 +345,22 @@ no_intr:
 	return (0);
 
 fail:
-	intsmb_detach(dev);
+	intsmb_release_resources(dev);
 	return (error);
 }
 
 static int
 intsmb_detach(device_t dev)
 {
-	struct intsmb_softc *sc = device_get_softc(dev);
 	int error;
 
 	error = bus_generic_detach(dev);
-	if (error)
+	if (error) {
+		device_printf(dev, "bus detach failed\n");
 		return (error);
+	}
 
-	if (sc->smbus)
-		device_delete_child(dev, sc->smbus);
-	if (sc->irq_hand)
-		bus_teardown_intr(dev, sc->irq_res, sc->irq_hand);
-	if (sc->irq_res)
-		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
-	if (sc->io_res)
-		bus_release_resource(dev, SYS_RES_IOPORT, sc->io_rid,
-		    sc->io_res);
-	mtx_destroy(&sc->lock);
+	intsmb_release_resources(dev);
 	return (0);
 }