[PATCH V2] xhci: Reset TI usb controller on xhci shutdown

[wenxiong]

From: Wen Xiong <wenxiong@xxxxxxxxxxxxx>

Fixes kexec boot. Without a hard reset, TI pci usb chips will fail to
initialize in a kexec booted kernel.

Signed-off-by: Wen Xixong <wenxiong@xxxxxxxxxxxxx>
---
 drivers/usb/host/xhci-pci.c | 11 ++++++++++-
 drivers/usb/host/xhci.h     |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index a8889081ae82..36191639bf43 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -479,8 +479,10 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	    pdev->device == PCI_DEVICE_ID_ASMEDIA_3042_XHCI)
 		xhci->quirks |= XHCI_RESET_ON_RESUME;
 
-	if (pdev->vendor == PCI_VENDOR_ID_TI && pdev->device == 0x8241)
+	if (pdev->vendor == PCI_VENDOR_ID_TI && pdev->device == 0x8241) {
 		xhci->quirks |= XHCI_LIMIT_ENDPOINT_INTERVAL_7;
+		xhci->quirks |= XHCI_RESET_ON_SHUTDOWN;
+	}
 
 	if ((pdev->vendor == PCI_VENDOR_ID_BROADCOM ||
 	     pdev->vendor == PCI_VENDOR_ID_CAVIUM) &&
@@ -950,6 +952,13 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd)
 	/* Yet another workaround for spurious wakeups at shutdown with HSW */
 	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
 		pci_set_power_state(pdev, PCI_D3hot);
+
+	/* 
+	* TI xHCI controllers fail to initialize in a kexec 
+	* kernel without a PCI function reset
+	*/
+	if (xhci->quirks & XHCI_RESET_ON_SHUTDOWN)
+		pci_reset_function_locked(pdev);
 }
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index c7bfa7f028d3..e94a38e5f4ac 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1647,6 +1647,7 @@ struct xhci_hcd {
 #define XHCI_CDNS_SCTX_QUIRK	BIT_ULL(48)
 #define XHCI_ETRON_HOST	BIT_ULL(49)
 #define XHCI_LIMIT_ENDPOINT_INTERVAL_9 BIT_ULL(50)
+#define XHCI_RESET_ON_SHUTDOWN	BIT_ULL(51)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.52.0