If the user chooses to say "no" to CONFIG_CONFIG_USB_XHCI on a system
with an Intel Panther Point chipset, the PCI quirks code or the EHCI
driver will switch the ports over to the xHCI host, but the xHCI driver
will never load. The ports will be powered off and seem "dead" to the
user.
Fix this by only switching the ports over if CONFIG_USB_XHCI is turned
on.
This patch should be backported to stable kernels as old as 3.0,
that contain commit 69e848c2090aebba5698a1620604c7dccb448684
"Intel xhci: Support EHCI/xHCI port switching."
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Reported-by: Eric Anholt <eric.anholt@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Eric, I've tested this fix on my Ivy Bridge system, and it seems to work
fine. USB devices show up under EHCI even though CONFIG_USB_XHCI is
turned off.
Let me know if it doesn't work for you. I'll send it off to Greg
tomorrow unless I hear otherwise.
Sarah
drivers/usb/host/pci-quirks.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 32dada8..76c13cd 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -740,6 +740,11 @@ EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);
*/
void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
{
+ /* Don't switchover the ports if the user hasn't compiled the xHCI
+ * driver. Otherwise they will see "dead" USB ports that don't power
+ * the devices.
+ */
+#ifdef CONFIG_USB_XHCI
u32 ports_available;
ports_available = 0xffffffff;
@@ -767,6 +772,13 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
&ports_available);
dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
"to xHCI: 0x%x\n", ports_available);
+#else
+ dev_warn(&xhci_pdev->dev,
+ "CONFIG_USB_XHCI_HCD is turned off, "
+ "defaulting to EHCI.\n");
+ dev_warn(&xhci_pdev->dev,
+ "USB 3.0 devices will work at USB 2.0 speeds.\n");
+#endif
}
EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);
--
1.7.9
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