xhci: add handler for only one interrupt line

Current xHCI driver only supports one "interrupter", meaning we will
only use one MSI/MSI-X interrupt line. Thus, add handler only to the
first interrupt line.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Co-developed-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231201150647.1307406-13-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-pci.c

@@ -95,10 +95,9 @@ static void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
 
 	if (hcd->msix_enabled) {
 		struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
-		int i;
 
-		for (i = 0; i < xhci->msix_count; i++)
-			synchronize_irq(pci_irq_vector(pdev, i));
+		/* for now, the driver only supports one primary interrupter */
+		synchronize_irq(pci_irq_vector(pdev, 0));
 	}
 }
 
@@ -112,15 +111,7 @@ static void xhci_cleanup_msix(struct xhci_hcd *xhci)
 	if (hcd->irq > 0)
 		return;
 
-	if (hcd->msix_enabled) {
-		int i;
-
-		for (i = 0; i < xhci->msix_count; i++)
-			free_irq(pci_irq_vector(pdev, i), xhci_to_hcd(xhci));
-	} else {
-		free_irq(pci_irq_vector(pdev, 0), xhci_to_hcd(xhci));
-	}
-
+	free_irq(pci_irq_vector(pdev, 0), xhci_to_hcd(xhci));
 	pci_free_irq_vectors(pdev);
 	hcd->msix_enabled = 0;
 }
@@ -159,9 +150,9 @@ static int xhci_setup_msi(struct xhci_hcd *xhci)
  */
 static int xhci_setup_msix(struct xhci_hcd *xhci)
 {
-	int i, ret;
 	struct usb_hcd *hcd = xhci_to_hcd(xhci);
 	struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+	int ret;
 
 	/*
 	 * calculate number of msi-x vectors supported.
@@ -181,22 +172,16 @@ static int xhci_setup_msix(struct xhci_hcd *xhci)
 		return ret;
 	}
 
-	for (i = 0; i < xhci->msix_count; i++) {
-		ret = request_irq(pci_irq_vector(pdev, i), xhci_msi_irq, 0,
-				"xhci_hcd", xhci_to_hcd(xhci));
-		if (ret)
-			goto disable_msix;
+	ret = request_irq(pci_irq_vector(pdev, 0), xhci_msi_irq, 0, "xhci_hcd",
+			  xhci_to_hcd(xhci));
+	if (ret) {
+		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable MSI-X interrupt");
+		pci_free_irq_vectors(pdev);
+		return ret;
 	}
 
 	hcd->msix_enabled = 1;
 	return ret;
-
-disable_msix:
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable MSI-X interrupt");
-	while (--i >= 0)
-		free_irq(pci_irq_vector(pdev, i), xhci_to_hcd(xhci));
-	pci_free_irq_vectors(pdev);
-	return ret;
 }
 
 static int xhci_try_enable_msi(struct usb_hcd *hcd)