usb: core: hcd: make hcd->irq unsigned

There's really no point in having hcd->irq as a
signed integer when we consider the fact that
IRQ 0 means NO_IRQ. In order to avoid confusion,
make hcd->irq unsigned and fix users who were
passing -1 as the IRQ number to usb_add_hcd.

Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 34b9edd..831fa40 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -899,7 +899,7 @@
 	ohci_usb_reset (ohci);
 	ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
 	free_irq(hcd->irq, hcd);
-	hcd->irq = -1;
+	hcd->irq = 0;
 
 	if (quirk_zfmicro(ohci))
 		del_timer(&ohci->unlink_watchdog);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 3a03324..9e71f7c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2396,7 +2396,7 @@
 	/* FIXME when MSI-X is supported and there are multiple vectors */
 	/* Clear the MSI-X event interrupt status */
 
-	if (hcd->irq != -1) {
+	if (hcd->irq) {
 		u32 irq_pending;
 		/* Acknowledge the PCI interrupt */
 		irq_pending = xhci_readl(xhci, &xhci->ir_set->irq_pending);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c939f5f..a629ad8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -224,13 +224,13 @@
 	int ret;
 
 	/* return if using legacy interrupt */
-	if (xhci_to_hcd(xhci)->irq >= 0)
+	if (xhci_to_hcd(xhci)->irq > 0)
 		return;
 
 	ret = xhci_free_msi(xhci);
 	if (!ret)
 		return;
-	if (pdev->irq >= 0)
+	if (pdev->irq > 0)
 		free_irq(pdev->irq, xhci_to_hcd(xhci));
 
 	return;
@@ -341,7 +341,7 @@
 	/* unregister the legacy interrupt */
 	if (hcd->irq)
 		free_irq(hcd->irq, hcd);
-	hcd->irq = -1;
+	hcd->irq = 0;
 
 	ret = xhci_setup_msix(xhci);
 	if (ret)
@@ -349,7 +349,7 @@
 		ret = xhci_setup_msi(xhci);
 
 	if (!ret)
-		/* hcd->irq is -1, we have MSI */
+		/* hcd->irq is 0, we have MSI */
 		return 0;
 
 	if (!pdev->irq) {