Patch "xhci: Identify USB 3.1 capable hosts by their port protocol capability" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

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

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
xhci-identify-usb-3.1-capable-hosts-by-their-port-protocol-capability.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Mathias Nyman <[email protected]>
Date: Fri, 6 Oct 2017 17:45:27 +0300
Subject: xhci: Identify USB 3.1 capable hosts by their port protocol capability

From: Mathias Nyman <[email protected]>

commit ea7d0d69426cab6747ed311c53f4142eb48b9454 upstream.

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.

---
 drivers/usb/host/xhci.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -4855,7 +4855,8 @@ int xhci_gen_setup(struct usb_hcd *hcd,
 		 */
 		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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/usb-hub-allow-reset-retry-for-usb2-devices-on-connect-bounce.patch queue-4.9/xhci-identify-usb-3.1-capable-hosts-by-their-port-protocol-capability.patch