This is a note to let you know that I've just added the patch titled
USB: EHCI: unlink QHs even after the controller has stopped
to the 3.14-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-ehci-unlink-qhs-even-after-the-controller-has-stopped.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7312b5ddd47fee2356baa78c5516ef8e04eed452 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 17 Sep 2014 11:23:54 -0400
Subject: USB: EHCI: unlink QHs even after the controller has stopped
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
commit 7312b5ddd47fee2356baa78c5516ef8e04eed452 upstream.
Old code in ehci-hcd tries to expedite disabling endpoints after the
controller has stopped, by destroying the endpoint's associated QH
without first unlinking the QH. This was necessary back when the
driver wasn't so careful about keeping track of the controller's
state.
But now we are careful about it, and the driver knows that when the
controller isn't running, no unlinking delay is needed. Furthermore,
skipping the unlink step will trigger a BUG() in qh_destroy() when the
preceding QH is released, because the link pointer will be non-NULL.
Removing the lines that skip the unlinking step and go directly to
QH_STATE_IDLE fixes the problem.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx>
Tested-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 2 --
1 file changed, 2 deletions(-)
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -965,8 +965,6 @@ rescan:
}
qh->exception = 1;
- if (ehci->rh_state < EHCI_RH_RUNNING)
- qh->qh_state = QH_STATE_IDLE;
switch (qh->qh_state) {
case QH_STATE_LINKED:
WARN_ON(!list_empty(&qh->qtd_list));
Patches currently in stable-queue which might be from stern@xxxxxxxxxxxxxxxxxxx are
queue-3.14/usb-hub-take-hub-hdev-reference-when-processing-from-eventlist.patch
queue-3.14/usb-ehci-unlink-qhs-even-after-the-controller-has-stopped.patch
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