Intel xhci: refactor EHCI/xHCI port switching

Make the Linux xHCI driver automatically try to switchover the EHCI ports to
xHCI when an Intel xHCI host is detected, and it also finds an Intel EHCI host.

This means we will no longer have to add Intel xHCI hosts to a quirks list when
the PCI device IDs change.  Simply continuing to add new Intel xHCI PCI device
IDs to the quirks list is not sustainable.

During suspend ports may be swicthed back to EHCI by BIOS and not properly
restored to xHCI at resume. Previously both EHCI and xHCI resume functions
switched ports back to XHCI, but it's enough to do it in xHCI only
because the hub driver doesn't start running again until after both hosts are resumed.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 0 insertions, 42 deletions

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 595d210655b6..6bd299e61f58 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -315,53 +315,11 @@ done:
  * Also they depend on separate root hub suspend/resume.
  */
 
-static bool usb_is_intel_switchable_ehci(struct pci_dev *pdev)
-{
-        return pdev->class == PCI_CLASS_SERIAL_USB_EHCI &&
-                pdev->vendor == PCI_VENDOR_ID_INTEL &&
-                (pdev->device == 0x1E26 ||
-                 pdev->device == 0x8C2D ||
-                 pdev->device == 0x8C26 ||
-                 pdev->device == 0x9C26);
-}
-
-static void ehci_enable_xhci_companion(void)
-{
-        struct pci_dev          *companion = NULL;
-
-        /* The xHCI and EHCI controllers are not on the same PCI slot */
-        for_each_pci_dev(companion) {
-                if (!usb_is_intel_switchable_xhci(companion))
-                        continue;
-                usb_enable_xhci_ports(companion);
-                return;
-        }
-}
-
 static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 {
         struct ehci_hcd         *ehci = hcd_to_ehci(hcd);
         struct pci_dev          *pdev = to_pci_dev(hcd->self.controller);
 
-        /* The BIOS on systems with the Intel Panther Point chipset may or may
-         * not support xHCI natively.  That means that during system resume, it
-         * may switch the ports back to EHCI so that users can use their
-         * keyboard to select a kernel from GRUB after resume from hibernate.
-         *
-         * The BIOS is supposed to remember whether the OS had xHCI ports
-         * enabled before resume, and switch the ports back to xHCI when the
-         * BIOS/OS semaphore is written, but we all know we can't trust BIOS
-         * writers.
-         *
-         * Unconditionally switch the ports back to xHCI after a system resume.
-         * We can't tell whether the EHCI or xHCI controller will be resumed
-         * first, so we have to do the port switchover in both drivers.  Writing
-         * a '1' to the port switchover registers should have no effect if the
-         * port was already switched over.
-         */
-        if (usb_is_intel_switchable_ehci(pdev))
-                ehci_enable_xhci_companion();
-
         if (ehci_resume(hcd, hibernated) != 0)
                 (void) ehci_pci_reinit(ehci, pdev);
         return 0;