openwrtv4/target/linux/apm821xx/patches-4.14/802-usb-xhci-force-msi-renesas-xhci.patch

From a0dc613140bab907a3d5787a7ae7b0638bf674d0 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@gmail.com>
Date: Thu, 23 Jun 2016 20:28:20 +0200
Subject: [PATCH] usb: xhci: force MSI for uPD720201 and
 uPD720202

The APM82181 does not support MSI-X. When probed, it will
produce a noisy warning.

---
 drivers/usb/host/pci-quirks.c | 362 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 362 insertions(+)

--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -213,7 +213,7 @@ static void xhci_pci_quirks(struct devic
 		xhci->quirks |= XHCI_TRUST_TX_LENGTH;
 	if (pdev->vendor == PCI_VENDOR_ID_RENESAS &&
 			pdev->device == 0x0015)
-		xhci->quirks |= XHCI_RESET_ON_RESUME;
+		xhci->quirks |= XHCI_RESET_ON_RESUME | XHCI_FORCE_MSI;
 	if (pdev->vendor == PCI_VENDOR_ID_VIA)
 		xhci->quirks |= XHCI_RESET_ON_RESUME;
 
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -372,10 +372,14 @@ static int xhci_try_enable_msi(struct us
 		free_irq(hcd->irq, hcd);
 	hcd->irq = 0;
 
-	ret = xhci_setup_msix(xhci);
-	if (ret)
-		/* fall back to msi*/
+	if (xhci->quirks & XHCI_FORCE_MSI) {
 		ret = xhci_setup_msi(xhci);
+	} else {
+		ret = xhci_setup_msix(xhci);
+		if (ret)
+			/* fall back to msi*/
+			ret = xhci_setup_msi(xhci);
+	}
 
 	if (!ret) {
 		hcd->msi_enabled = 1;
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1854,6 +1854,7 @@ struct xhci_hcd {
 	/* support xHCI 0.96 spec USB2 software LPM */
 	unsigned		sw_lpm_support:1;
 	/* support xHCI 1.0 spec USB2 hardware LPM */
+#define XHCI_FORCE_MSI		(1 << 24)
 	unsigned		hw_lpm_support:1;
 	/* cached usb2 extened protocol capabilites */
 	u32                     *ext_caps;