[PATCH 1/2] xhci: provide usb_disable_xhci_ports function for Intel chipsets.

[Denis Turischev <denis@compulab.co.il>]

Some devices with Intel Panther Point chipset may require switchover
usb ports from XHCI back to EHCI controller before shutdown.
Overwise various BIOS bugs related to power management may be
triggered.

Signed-off-by: Denis Turischev <denis@compulab.co.il>
---
 drivers/usb/host/pci-quirks.c |   14 ++++++++++++++
 drivers/usb/host/pci-quirks.h |    1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index df0828c..b19a84a 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -800,6 +800,20 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
 }
 EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);

+void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
+{
+	u32		ports_available;
+
+	ports_available = 0x0;
+
+	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
+			cpu_to_le32(ports_available));
+
+	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
+			cpu_to_le32(ports_available));
+}
+EXPORT_SYMBOL_GPL(usb_disable_xhci_ports);
+
 /**
  * PCI Quirks for xHCI.
  *
diff --git a/drivers/usb/host/pci-quirks.h b/drivers/usb/host/pci-quirks.h
index b1002a8..ef004a5 100644
--- a/drivers/usb/host/pci-quirks.h
+++ b/drivers/usb/host/pci-quirks.h
@@ -10,6 +10,7 @@ void usb_amd_quirk_pll_disable(void);
 void usb_amd_quirk_pll_enable(void);
 bool usb_is_intel_switchable_xhci(struct pci_dev *pdev);
 void usb_enable_xhci_ports(struct pci_dev *xhci_pdev);
+void usb_disable_xhci_ports(struct pci_dev *xhci_pdev);
 #else
 static inline void usb_amd_quirk_pll_disable(void) {}
 static inline void usb_amd_quirk_pll_enable(void) {}
-- 
1.7.9.5