From dcf83ff0e9e93349f750645be4d2b4d28ab05d12 Mon Sep 17 00:00:00 2001
From: Marius Strobl <marius@FreeBSD.org>
Date: Sat, 27 Dec 2014 21:50:47 +0000
Subject: [PATCH] Improve/fix interrupt allocation/setup/release: - Simplify
 MSI allocation to what is actually needed for a single one. - Release the MSI
 and the corresponding bus resource as appropriate when   either the interrupt
 resource cannot be allocated or setting up the   interrupt fails. - Error out
 when interrupt allocation or setup fails and polling is   disabled. - Release
 the MSI after the corresponding bus resource so the former is   not leaked on
 detach. - Remove a redundant softc member.

MFC after:	3 days
---
 sys/dev/usb/controller/xhci.h     |  1 -
 sys/dev/usb/controller/xhci_pci.c | 45 ++++++++++++++++---------------
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/sys/dev/usb/controller/xhci.h b/sys/dev/usb/controller/xhci.h
index 7352e9c84ea..a6758558604 100644
--- a/sys/dev/usb/controller/xhci.h
+++ b/sys/dev/usb/controller/xhci.h
@@ -452,7 +452,6 @@ struct xhci_softc {
 
 	struct usb_device	*sc_devices[XHCI_MAX_DEVICES];
 	struct resource		*sc_io_res;
-	int			sc_irq_rid;
 	struct resource		*sc_irq_res;
 
 	void			*sc_intr_hdl;
diff --git a/sys/dev/usb/controller/xhci_pci.c b/sys/dev/usb/controller/xhci_pci.c
index efa69c2c9a7..c39842c431a 100644
--- a/sys/dev/usb/controller/xhci_pci.c
+++ b/sys/dev/usb/controller/xhci_pci.c
@@ -203,21 +203,19 @@ xhci_pci_attach(device_t self)
 
 	usb_callout_init_mtx(&sc->sc_callout, &sc->sc_bus.bus_mtx, 0);
 
-	sc->sc_irq_rid = 0;
+	rid = 0;
 	if (xhci_use_msi) {
-		count = pci_msi_count(self);
-		if (count >= 1) {
-			count = 1;
-			if (pci_alloc_msi(self, &count) == 0) {
-				if (bootverbose)
-					device_printf(self, "MSI enabled\n");
-				sc->sc_irq_rid = 1;
-			}
+		count = 1;
+		if (pci_alloc_msi(self, &count) == 0) {
+			if (bootverbose)
+				device_printf(self, "MSI enabled\n");
+			rid = 1;
 		}
 	}
-	sc->sc_irq_res = bus_alloc_resource_any(self, SYS_RES_IRQ,
-	    &sc->sc_irq_rid, RF_SHAREABLE | RF_ACTIVE);
+	sc->sc_irq_res = bus_alloc_resource_any(self, SYS_RES_IRQ, &rid,
+	    RF_ACTIVE | (rid != 0 ? 0 : RF_SHAREABLE));
 	if (sc->sc_irq_res == NULL) {
+		pci_release_msi(self);
 		device_printf(self, "Could not allocate IRQ\n");
 		/* goto error; FALLTHROUGH - use polling */
 	}
@@ -234,16 +232,22 @@ xhci_pci_attach(device_t self)
 		err = bus_setup_intr(self, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
 		    NULL, (driver_intr_t *)xhci_interrupt, sc, &sc->sc_intr_hdl);
 		if (err != 0) {
+			bus_release_resource(self, SYS_RES_IRQ,
+			    rman_get_rid(sc->sc_irq_res), sc->sc_irq_res);
+			sc->sc_irq_res = NULL;
+			pci_release_msi(self);
 			device_printf(self, "Could not setup IRQ, err=%d\n", err);
 			sc->sc_intr_hdl = NULL;
 		}
 	}
-	if (sc->sc_irq_res == NULL || sc->sc_intr_hdl == NULL ||
-	    xhci_use_polling() != 0) {
-		device_printf(self, "Interrupt polling at %dHz\n", hz);
-		USB_BUS_LOCK(&sc->sc_bus);
-		xhci_interrupt_poll(sc);
-		USB_BUS_UNLOCK(&sc->sc_bus);
+	if (sc->sc_irq_res == NULL || sc->sc_intr_hdl == NULL) {
+		if (xhci_use_polling() != 0) {
+			device_printf(self, "Interrupt polling at %dHz\n", hz);
+			USB_BUS_LOCK(&sc->sc_bus);
+			xhci_interrupt_poll(sc);
+			USB_BUS_UNLOCK(&sc->sc_bus);
+		} else
+			goto error;
 	}
 
 	/* On Intel chipsets reroute ports from EHCI to XHCI controller. */
@@ -307,11 +311,10 @@ xhci_pci_detach(device_t self)
 		sc->sc_intr_hdl = NULL;
 	}
 	if (sc->sc_irq_res) {
-		if (sc->sc_irq_rid == 1)
-			pci_release_msi(self);
-		bus_release_resource(self, SYS_RES_IRQ, sc->sc_irq_rid,
-		    sc->sc_irq_res);
+		bus_release_resource(self, SYS_RES_IRQ,
+		    rman_get_rid(sc->sc_irq_res), sc->sc_irq_res);
 		sc->sc_irq_res = NULL;
+		pci_release_msi(self);
 	}
 	if (sc->sc_io_res) {
 		bus_release_resource(self, SYS_RES_MEMORY, PCI_XHCI_CBMEM,