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authorSarah Sharp <sarah.a.sharp@linux.intel.com>2012-04-16 17:56:47 (GMT)
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2012-05-03 20:16:32 (GMT)
commit51c9e6c7732b67769c0a514d31f505e49fa82dd4 (patch)
treea1f97e55ac2657a7b1f02c3637f4e03ccac4a884
parent9c745995ae5c4ff787f34a359de908facc11ee00 (diff)
downloadlinux-51c9e6c7732b67769c0a514d31f505e49fa82dd4.tar.xz
xhci: Avoid dead ports when CONFIG_USB_XHCI_HCD=n
If the user chooses to say "no" to CONFIG_USB_XHCI_HCD 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_HCD is either compiled in, or compiled as a module. 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@linux.intel.com> Reported-by: Eric Anholt <eric.anholt@intel.com> Reported-by: David Bein <d.bein@f5.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/usb/host/pci-quirks.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 32dada8..39b2612 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -9,6 +9,7 @@
*/
#include <linux/types.h>
+#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
@@ -742,6 +743,19 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
{
u32 ports_available;
+ /* 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.
+ */
+ if (!IS_ENABLED(CONFIG_USB_XHCI_HCD)) {
+ 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");
+ return;
+ }
+
ports_available = 0xffffffff;
/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
* Register, to turn on SuperSpeed terminations for all