[3.19.y-ckt stable] Patch "xhci: resume USB 3 roothub first" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    xhci: resume USB 3 roothub first

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt20.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 80f1d0eef82d28844955bb5a87e322d16ac1fbcc Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman at linux.intel.com>
Date: Fri, 8 Apr 2016 16:25:06 +0300
Subject: xhci: resume USB 3 roothub first

commit 671ffdff5b13314b1fc65d62cf7604b873fb5dc4 upstream.

Give USB3 devices a better chance to enumerate at USB 3 speeds if
they are connected to a suspended host.
Solves an issue with NEC uPD720200 host hanging when partially
enumerating a USB3 device as USB2 after host controller runtime resume.

Tested-by: Mike Murdoch <main.haarp at gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/host/xhci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 37c469f..643a9f9 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1116,8 +1116,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		/* Resume root hubs only when have pending events. */
 		status = readl(&xhci->op_regs->status);
 		if (status & STS_EINT) {
-			usb_hcd_resume_root_hub(hcd);
 			usb_hcd_resume_root_hub(xhci->shared_hcd);
+			usb_hcd_resume_root_hub(hcd);
 		}
 	}

@@ -1132,10 +1132,10 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)

 	/* Re-enable port polling. */
 	xhci_dbg(xhci, "%s: starting port polling.\n", __func__);
-	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
-	usb_hcd_poll_rh_status(hcd);
 	set_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
 	usb_hcd_poll_rh_status(xhci->shared_hcd);
+	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+	usb_hcd_poll_rh_status(hcd);

 	return retval;
 }
--
2.7.4