From a448c9d8c58ff7d3f8cc2a8f835065460099b22d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 19 Aug 2009 12:22:44 -0400 Subject: USB: EHCI: change deschedule logic for interrupt QHs This patch (as1281) changes the way ehci-hcd deschedules interrupt QHs, copying the approach used for async QHs. The caller is no longer responsible for rescheduling the QH if its queue is non-empty; instead the reschedule is done directly by intr_deschedule(), after calling qh_completions(). This is exactly the same as how end_unlink_async() works. ehci_urb_dequeue() and intr_deschedule() now correctly handle the case where they are called while another interrupt URB for the same QH is being given back. This was a surprisingly large blind spot. And scan_periodic() now respects the new needs_rescan flag. Signed-off-by: Alan Stern CC: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) (limited to 'drivers/usb/host/ehci-hcd.c') diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index d7e85b6231b..4f89d7ffd53 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -934,8 +934,9 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) break; switch (qh->qh_state) { case QH_STATE_LINKED: + case QH_STATE_COMPLETING: intr_deschedule (ehci, qh); - /* FALL THROUGH */ + break; case QH_STATE_IDLE: qh_completions (ehci, qh); break; @@ -944,23 +945,6 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) qh, qh->qh_state); goto done; } - - /* reschedule QH iff another request is queued */ - if (!list_empty (&qh->qtd_list) - && HC_IS_RUNNING (hcd->state)) { - rc = qh_schedule(ehci, qh); - - /* An error here likely indicates handshake failure - * or no space left in the schedule. Neither fault - * should happen often ... - * - * FIXME kill the now-dysfunctional queued urbs - */ - if (rc != 0) - ehci_err(ehci, - "can't reschedule qh %p, err %d", - qh, rc); - } break; case PIPE_ISOCHRONOUS: @@ -1079,12 +1063,10 @@ ehci_endpoint_reset(struct usb_hcd *hcd, struct usb_host_endpoint *ep) * while the QH is active. Unlink it now; * re-linking will call qh_refresh(). */ - if (eptype == USB_ENDPOINT_XFER_BULK) { + if (eptype == USB_ENDPOINT_XFER_BULK) unlink_async(ehci, qh); - } else { + else intr_deschedule(ehci, qh); - (void) qh_schedule(ehci, qh); - } } } spin_unlock_irqrestore(&ehci->lock, flags); -- cgit v1.2.3