Patch "usb: Use the USB_SS_MULT() macro to get the burst multiplier." has been added to the 4.2-stable tree

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

usb: Use the USB_SS_MULT() macro to get the burst multiplier.

to the 4.2-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:
usb-use-the-usb_ss_mult-macro-to-get-the-burst-multiplier.patch
and it can be found in the queue-4.2 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: Mon, 21 Sep 2015 17:46:09 +0300
Subject: usb: Use the USB_SS_MULT() macro to get the burst multiplier.

From: Mathias Nyman <[email protected]>

commit ff30cbc8da425754e8ab96904db1d295bd034f27 upstream.

Bits 1:0 of the bmAttributes are used for the burst multiplier. The rest of the bits used to be reserved (zero), but USB3.1 takes bit 7 into use.

Use the existing USB_SS_MULT() macro instead to make sure the mult value and hence max packet calculations are correct for USB3.1 devices.

Note that burst multiplier in bmAttributes is zero based and that the USB_SS_MULT() macro adds one.

---
 drivers/usb/core/config.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -112,7 +112,7 @@ static void usb_parse_ss_endpoint_compan
 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
 		ep->ss_ep_comp.bmAttributes = 16;
 	} else if (usb_endpoint_xfer_isoc(&ep->desc) &&
-			desc->bmAttributes > 2) {
+		   USB_SS_MULT(desc->bmAttributes) > 3) {
 		dev_warn(ddev, "Isoc endpoint has Mult of %d in "
 				"config %d interface %d altsetting %d ep %d: "
 				"setting to 3\n", desc->bmAttributes + 1,

@@ -121,7 +121,8 @@ static void usb_parse_ss_endpoint_compan
 	}
 
 	if (usb_endpoint_xfer_isoc(&ep->desc))
-		max_tx = (desc->bMaxBurst + 1) * (desc->bmAttributes + 1) *
+		max_tx = (desc->bMaxBurst + 1) *
+			(USB_SS_MULT(desc->bmAttributes)) *
 			usb_endpoint_maxp(&ep->desc);
 	else if (usb_endpoint_xfer_int(&ep->desc))
 		max_tx = usb_endpoint_maxp(&ep->desc) *

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

queue-4.2/usb-xhci-exit-early-in-xhci_setup_device-if-we-re-halted-or-dying.patch queue-4.2/xhci-give-command-abortion-one-more-chance-before-killing-xhci.patch queue-4.2/usb-xhci-clear-xhci_state_dying-on-start.patch queue-4.2/xhci-move-xhci_pme_quirk-behind-ifdef-config_pm.patch queue-4.2/usb-xhci-add-support-for-urb_zero_packet-to-bulk-sg-transfers.patch queue-4.2/usb-xhci-stop-everything-on-the-first-call-to-xhci_stop.patch queue-4.2/xhci-init-command-timeout-timer-earlier-to-avoid-deleting-it-uninitialized.patch queue-4.2/usb-use-the-usb_ss_mult-macro-to-get-the-burst-multiplier.patch queue-4.2/usb-xhci-lock-mutex-on-xhci_stop.patch queue-4.2/xhci-change-xhci-1.0-only-restrictions-to-support-xhci-1.1.patch