USB: EHCI: update toggle state for linked QHs
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@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: David <david@unsolicited.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 1976b1b..3192f68 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -93,22 +93,6 @@
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);
@@ -850,7 +834,6 @@
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;
}
@@ -881,7 +864,7 @@
}
}
- /* 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);