This patch (as1245) fixes a bug in ehci-hcd. When an URB is queued
for an endpoint whose QH is already in the LINKED state, the QH
doesn't get refreshed. As a result, if usb_clear_halt() was called
during the time that the QH was linked but idle, the data toggle value
in the QH doesn't get reset.
The symptom is that after a clear_halt, data gets lost and transfers
time out. This problem is starting to show up now because the
"ehci-hcd unlink speedups" patch causes QHs with no queued URBs to
remain linked for a suitable time.
The patch utilizes the new endpoint_reset mechanism to fix the
problem. When an endpoint is reset, the new method forcibly unlinks
the QH (if necessary) and safely updates the toggle value. This
allows qh_update() to be simplified and avoids using usb_device's
toggle bits in a rather unintuitive way.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
CC: David Brownell <david-b@xxxxxxxxxxx>
Tested-by: David <david@xxxxxxxxxxxxxxx>
---
This hasn't been tested with interrupt endpoints, only bulk endpoints.
On the other hand, I've never heard of an interrupt endpoint being
halted (maybe it could happen with an invalid HID output report).
Index: usb-2.6/drivers/usb/host/ehci-q.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-q.c
+++ usb-2.6/drivers/usb/host/ehci-q.c
@@ -93,22 +93,6 @@ qh_update (struct ehci_hcd *ehci, struct
qh->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
qh->hw_alt_next = EHCI_LIST_END(ehci);
- /* Except for control endpoints, we make hardware maintain data
- * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
- * and set the pseudo-toggle in udev. Only usb_clear_halt() will
- * ever clear it.
- */
- if (!(qh->hw_info1 & cpu_to_hc32(ehci, 1 << 14))) {
- unsigned is_out, epnum;
-
- is_out = !(qtd->hw_token & cpu_to_hc32(ehci, 1 << 8));
- epnum = (hc32_to_cpup(ehci, &qh->hw_info1) >> 8) & 0x0f;
- if (unlikely (!usb_gettoggle (qh->dev, epnum, is_out))) {
- qh->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
- usb_settoggle (qh->dev, epnum, is_out, 1);
- }
- }
-
/* HC must see latest qtd and qh data before we clear ACTIVE+HALT */
wmb ();
qh->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
@@ -893,7 +877,6 @@ done:
qh->qh_state = QH_STATE_IDLE;
qh->hw_info1 = cpu_to_hc32(ehci, info1);
qh->hw_info2 = cpu_to_hc32(ehci, info2);
- usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
qh_refresh (ehci, qh);
return qh;
}
@@ -928,7 +911,7 @@ static void qh_link_async (struct ehci_h
}
}
- /* clear halt and/or toggle; and maybe recover from silicon quirk */
+ /* clear halt and maybe recover from silicon quirk */
if (qh->qh_state == QH_STATE_IDLE)
qh_refresh (ehci, qh);
Index: usb-2.6/drivers/usb/host/ehci-hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hcd.c
+++ usb-2.6/drivers/usb/host/ehci-hcd.c
@@ -1026,6 +1026,51 @@ done:
return;
}
+static void
+ehci_endpoint_reset(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
+{
+ struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+ struct ehci_qh *qh;
+ int eptype = usb_endpoint_type(&ep->desc);
+
+ if (eptype != USB_ENDPOINT_XFER_BULK && eptype != USB_ENDPOINT_XFER_INT)
+ return;
+
+ rescan:
+ spin_lock_irq(&ehci->lock);
+ qh = ep->hcpriv;
+
+ /* For Bulk and Interrupt endpoints we maintain the toggle state
+ * in the hardware; the toggle bits in udev aren't used at all.
+ * When an endpoint is reset by usb_clear_halt() we must reset
+ * the toggle bit in the QH.
+ */
+ if (qh) {
+ if (!list_empty(&qh->qtd_list)) {
+ WARN_ONCE(1, "clear_halt for a busy endpoint\n");
+ } else if (qh->qh_state == QH_STATE_IDLE) {
+ qh->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
+ } else {
+ /* It's not safe to write into the overlay area
+ * while the QH is active. Unlink it first and
+ * wait for the unlink to complete.
+ */
+ if (qh->qh_state == QH_STATE_LINKED) {
+ if (eptype == USB_ENDPOINT_XFER_BULK) {
+ unlink_async(ehci, qh);
+ } else {
+ intr_deschedule(ehci, qh);
+ (void) qh_schedule(ehci, qh);
+ }
+ }
+ spin_unlock_irq(&ehci->lock);
+ schedule_timeout_uninterruptible(1);
+ goto rescan;
+ }
+ }
+ spin_unlock_irq(&ehci->lock);
+}
+
static int ehci_get_frame (struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
Index: usb-2.6/drivers/usb/host/ehci-au1xxx.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-au1xxx.c
+++ usb-2.6/drivers/usb/host/ehci-au1xxx.c
@@ -97,6 +97,7 @@ static const struct hc_driver ehci_au1xx
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
Index: usb-2.6/drivers/usb/host/ehci-fsl.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-fsl.c
+++ usb-2.6/drivers/usb/host/ehci-fsl.c
@@ -309,6 +309,7 @@ static const struct hc_driver ehci_fsl_h
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
Index: usb-2.6/drivers/usb/host/ehci-ixp4xx.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-ixp4xx.c
+++ usb-2.6/drivers/usb/host/ehci-ixp4xx.c
@@ -51,6 +51,7 @@ static const struct hc_driver ixp4xx_ehc
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
.get_frame_number = ehci_get_frame,
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
Index: usb-2.6/drivers/usb/host/ehci-orion.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-orion.c
+++ usb-2.6/drivers/usb/host/ehci-orion.c
@@ -149,6 +149,7 @@ static const struct hc_driver ehci_orion
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
Index: usb-2.6/drivers/usb/host/ehci-pci.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-pci.c
+++ usb-2.6/drivers/usb/host/ehci-pci.c
@@ -388,6 +388,7 @@ static const struct hc_driver ehci_pci_h
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
Index: usb-2.6/drivers/usb/host/ehci-ppc-of.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-ppc-of.c
+++ usb-2.6/drivers/usb/host/ehci-ppc-of.c
@@ -61,6 +61,7 @@ static const struct hc_driver ehci_ppc_o
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
Index: usb-2.6/drivers/usb/host/ehci-ps3.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-ps3.c
+++ usb-2.6/drivers/usb/host/ehci-ps3.c
@@ -65,6 +65,7 @@ static const struct hc_driver ps3_ehci_h
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
+ .endpoint_reset = ehci_endpoint_reset,
.get_frame_number = ehci_get_frame,
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
--
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