Commit ea7d0d69 authored Oct 06, 2017 by Mathias Nyman Committed by Greg Kroah-Hartman Oct 17, 2017

xhci: Identify USB 3.1 capable hosts by their port protocol capability



Many USB 3.1 capable hosts never updated the Serial Bus Release Number
(SBRN) register to USB 3.1 from USB 3.0

xhci driver identified USB 3.1 capable hosts based on this SBRN register,
which according to specs "contains the release of the Universal Serial
Bus Specification with which this Universal Serial Bus Host Controller
module is compliant." but still in october 2017 gives USB 3.0 as
the only possible option.

Make an additional check for USB 3.1 support and enable it if the xHCI
supported protocol capablity lists USB 3.1 capable ports.

Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 33d930e5

drivers/usb/host/xhci.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -4805,7 +4805,8 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
		*/
		hcd->has_tt = 1;
		} else {
		if (xhci->sbrn == 0x31) {
		/* Some 3.1 hosts return sbrn 0x30, can't rely on sbrn alone */
		if (xhci->sbrn == 0x31 \|\| xhci->usb3_rhub.min_rev >= 1) {
		xhci_info(xhci, "Host supports USB 3.1 Enhanced SuperSpeed\n");
		hcd->speed = HCD_USB31;
		hcd->self.root_hub->speed = USB_SPEED_SUPER_PLUS;

Admin message