xhci: Fix front USB ports on ASUS PRIME B350M-A

commit 191edc5 upstream.

When a USB device gets plugged on ASUS PRIME B350M-A's front ports, the
xHC stops working:
[  549.114587] xhci_hcd 0000:02:00.0: WARN: xHC CMD_RUN timeout
[  549.114608] suspend_common(): xhci_pci_suspend+0x0/0xc0 returns -110
[  549.114638] xhci_hcd 0000:02:00.0: can't suspend (hcd_pci_runtime_suspend returned -110)

Delay before running xHC command CMD_RUN can workaround the issue.

Use a new quirk to make the delay only targets to the affected xHC.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/host/xhci-pci.c

@@ -124,6 +124,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info())
 		xhci->quirks |= XHCI_AMD_PLL_FIX;
 
+	if (pdev->vendor == PCI_VENDOR_ID_AMD && pdev->device == 0x43bb)
+		xhci->quirks |= XHCI_SUSPEND_DELAY;
+
 	if (pdev->vendor == PCI_VENDOR_ID_AMD)
 		xhci->quirks |= XHCI_TRUST_TX_LENGTH;
 

drivers/usb/host/xhci.c

@@ -922,6 +922,9 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	del_timer_sync(&hcd->rh_timer);
 
+	if (xhci->quirks & XHCI_SUSPEND_DELAY)
+		usleep_range(1000, 1500);
+
 	spin_lock_irq(&xhci->lock);
 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &xhci->shared_hcd->flags);

drivers/usb/host/xhci.h

@@ -1571,6 +1571,7 @@ struct xhci_hcd {
 #define XHCI_MISSING_CAS	(1 << 24)
 #define XHCI_U2_DISABLE_WAKE	(1 << 27)
 #define XHCI_ASMEDIA_MODIFY_FLOWCONTROL	(1 << 28)
+#define XHCI_SUSPEND_DELAY	(1 << 30)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */