From 2f5bb665ba7a14c5842fa2e1cde2be039843a2a2 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 11 Jul 2012 11:21:43 -0400 Subject: USB: EHCI: add pointer to end of async-unlink list This patch (as1570) adds a pointer for the end of ehci-hcd's async-unlink list. The list (which is actually a queue) is singly linked, so having a pointer to its end makes adding new entries easier -- there's no longer any need to scan through the whole list. In principle it could be changed to a standard doubly-linked list. It turns out that doing so actually makes the code less clear, so I'm leaving it as is. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 9 ++------- drivers/usb/host/ehci-q.c | 2 ++ drivers/usb/host/ehci.h | 1 + 3 files changed, 5 insertions(+), 7 deletions(-) (limited to 'drivers/usb') diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index efee426a2465..8b75e4279a47 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -1041,14 +1041,9 @@ static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) /* defer till later if busy */ if (ehci->async_unlink) { - struct ehci_qh *last; - - for (last = ehci->async_unlink; - last->unlink_next; - last = last->unlink_next) - continue; qh->qh_state = QH_STATE_UNLINK_WAIT; - last->unlink_next = qh; + ehci->async_unlink_last->unlink_next = qh; + ehci->async_unlink_last = qh; /* start IAA cycle */ } else diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 8e80cde8c35e..5193612c96ea 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -1227,6 +1227,8 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) qh->qh_state = QH_STATE_UNLINK; ehci->async_unlink = qh; + if (!qh->unlink_next) + ehci->async_unlink_last = qh; prev = ehci->async; while (prev->qh_next.qh != qh) diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 3c6c07c0956a..475f23e10bbf 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -82,6 +82,7 @@ struct ehci_hcd { /* one per controller */ struct ehci_qh *async; struct ehci_qh *dummy; /* For AMD quirk use */ struct ehci_qh *async_unlink; + struct ehci_qh *async_unlink_last; struct ehci_qh *qh_scan_next; unsigned scanning : 1; -- cgit v1.2.3