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path: root/drivers/usb/host/ehci-q.c
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Diffstat (limited to 'drivers/usb/host/ehci-q.c')
-rw-r--r--drivers/usb/host/ehci-q.c91
1 files changed, 68 insertions, 23 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 68bf81e982d2..e3d2b627bfb3 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -139,6 +139,55 @@ qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
/*-------------------------------------------------------------------------*/
+static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
+
+static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
+ struct usb_host_endpoint *ep)
+{
+ struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+ struct ehci_qh *qh = ep->hcpriv;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ehci->lock, flags);
+ qh->clearing_tt = 0;
+ if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
+ && HC_IS_RUNNING(hcd->state))
+ qh_link_async(ehci, qh);
+ spin_unlock_irqrestore(&ehci->lock, flags);
+}
+
+static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
+ struct urb *urb, u32 token)
+{
+
+ /* If an async split transaction gets an error or is unlinked,
+ * the TT buffer may be left in an indeterminate state. We
+ * have to clear the TT buffer.
+ *
+ * Note: this routine is never called for Isochronous transfers.
+ */
+ if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
+#ifdef DEBUG
+ struct usb_device *tt = urb->dev->tt->hub;
+ dev_dbg(&tt->dev,
+ "clear tt buffer port %d, a%d ep%d t%08x\n",
+ urb->dev->ttport, urb->dev->devnum,
+ usb_pipeendpoint(urb->pipe), token);
+#endif /* DEBUG */
+ if (!ehci_is_TDI(ehci)
+ || urb->dev->tt->hub !=
+ ehci_to_hcd(ehci)->self.root_hub) {
+ if (usb_hub_clear_tt_buffer(urb) == 0)
+ qh->clearing_tt = 1;
+ } else {
+
+ /* REVISIT ARC-derived cores don't clear the root
+ * hub TT buffer in this way...
+ */
+ }
+ }
+}
+
static int qtd_copy_status (
struct ehci_hcd *ehci,
struct urb *urb,
@@ -195,28 +244,6 @@ static int qtd_copy_status (
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
token, status);
-
- /* if async CSPLIT failed, try cleaning out the TT buffer */
- if (status != -EPIPE
- && urb->dev->tt
- && !usb_pipeint(urb->pipe)
- && ((token & QTD_STS_MMF) != 0
- || QTD_CERR(token) == 0)
- && (!ehci_is_TDI(ehci)
- || urb->dev->tt->hub !=
- ehci_to_hcd(ehci)->self.root_hub)) {
-#ifdef DEBUG
- struct usb_device *tt = urb->dev->tt->hub;
- dev_dbg (&tt->dev,
- "clear tt buffer port %d, a%d ep%d t%08x\n",
- urb->dev->ttport, urb->dev->devnum,
- usb_pipeendpoint (urb->pipe), token);
-#endif /* DEBUG */
- /* REVISIT ARC-derived cores don't clear the root
- * hub TT buffer in this way...
- */
- usb_hub_clear_tt_buffer(urb);
- }
}
return status;
@@ -407,9 +434,16 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
/* qh unlinked; token in overlay may be most current */
if (state == QH_STATE_IDLE
&& cpu_to_hc32(ehci, qtd->qtd_dma)
- == qh->hw_current)
+ == qh->hw_current) {
token = hc32_to_cpu(ehci, qh->hw_token);
+ /* An unlink may leave an incomplete
+ * async transaction in the TT buffer.
+ * We have to clear it.
+ */
+ ehci_clear_tt_buffer(ehci, qh, urb, token);
+ }
+
/* force halt for unlinked or blocked qh, so we'll
* patch the qh later and so that completions can't
* activate it while we "know" it's stopped.
@@ -435,6 +469,13 @@ halt:
&& (qtd->hw_alt_next
& EHCI_LIST_END(ehci)))
last_status = -EINPROGRESS;
+
+ /* As part of low/full-speed endpoint-halt processing
+ * we must clear the TT buffer (11.17.5).
+ */
+ if (unlikely(last_status != -EINPROGRESS &&
+ last_status != -EREMOTEIO))
+ ehci_clear_tt_buffer(ehci, qh, urb, token);
}
/* if we're removing something not at the queue head,
@@ -864,6 +905,10 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
__hc32 dma = QH_NEXT(ehci, qh->qh_dma);
struct ehci_qh *head;
+ /* Don't link a QH if there's a Clear-TT-Buffer pending */
+ if (unlikely(qh->clearing_tt))
+ return;
+
/* (re)start the async schedule? */
head = ehci->async;
timer_action_done (ehci, TIMER_ASYNC_OFF);