From e7e7c360fb07020b24652843aec442325baad0ce Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 13 Jul 2007 15:46:29 -0400
Subject: UHCI: short control URBs get a status stage
It has recently been pointed out that short control transfers should
have a status stage, even if they generate an error because
URB_SHORT_NOT_OK was set. This patch (as935) changes uhci-hcd to
enable the status stage when this happens.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/usb/host/uhci-q.c | 59 ++++++++++++++++++++++++++++++-----------------
1 file changed, 38 insertions(+), 21 deletions(-)
(limited to 'drivers/usb')
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index 4aed305..3bb908c 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -827,8 +827,10 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
* If direction is "send", change the packet ID from SETUP (0x2D)
* to OUT (0xE1). Else change it from SETUP to IN (0x69) and
* set Short Packet Detect (SPD) for all data packets.
+ *
+ * 0-length transfers always get treated as "send".
*/
- if (usb_pipeout(urb->pipe))
+ if (usb_pipeout(urb->pipe) || len == 0)
destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
else {
destination ^= (USB_PID_SETUP ^ USB_PID_IN);
@@ -839,7 +841,12 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
* Build the DATA TDs
*/
while (len > 0) {
- int pktsze = min(len, maxsze);
+ int pktsze = maxsze;
+
+ if (len <= pktsze) { /* The last data packet */
+ pktsze = len;
+ status &= ~TD_CTRL_SPD;
+ }
td = uhci_alloc_td(uhci);
if (!td)
@@ -866,20 +873,10 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
goto nomem;
*plink = LINK_TO_TD(td);
- /*
- * It's IN if the pipe is an output pipe or we're not expecting
- * data back.
- */
- destination &= ~TD_TOKEN_PID_MASK;
- if (usb_pipeout(urb->pipe) || !urb->transfer_buffer_length)
- destination |= USB_PID_IN;
- else
- destination |= USB_PID_OUT;
-
+ /* Change direction for the status transaction */
+ destination ^= (USB_PID_IN ^ USB_PID_OUT);
destination |= TD_TOKEN_TOGGLE; /* End in Data1 */
- status &= ~TD_CTRL_SPD;
-
uhci_add_td_to_urbp(td, urbp);
uhci_fill_td(td, status | TD_CTRL_IOC,
destination | uhci_explen(0), 0);
@@ -1185,10 +1182,18 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
}
}
+ /* Did we receive a short packet? */
} else if (len < uhci_expected_length(td_token(td))) {
- /* We received a short packet */
- if (urb->transfer_flags & URB_SHORT_NOT_OK)
+ /* For control transfers, go to the status TD if
+ * this isn't already the last data TD */
+ if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+ if (td->list.next != urbp->td_list.prev)
+ ret = 1;
+ }
+
+ /* For bulk and interrupt, this may be an error */
+ else if (urb->transfer_flags & URB_SHORT_NOT_OK)
ret = -EREMOTEIO;
/* Fixup needed only if this isn't the URB's last TD */
@@ -1208,10 +1213,6 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
err:
if (ret < 0) {
- /* In case a control transfer gets an error
- * during the setup stage */
- urb->actual_length = max(urb->actual_length, 0);
-
/* Note that the queue has stopped and save
* the next toggle value */
qh->element = UHCI_PTR_TERM;
@@ -1489,9 +1490,25 @@ __acquires(uhci->lock)
{
struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+ if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+
+ /* urb->actual_length < 0 means the setup transaction didn't
+ * complete successfully. Either it failed or the URB was
+ * unlinked first. Regardless, don't confuse people with a
+ * negative length. */
+ urb->actual_length = max(urb->actual_length, 0);
+
+ /* Report erroneous short transfers */
+ if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
+ urb->actual_length <
+ urb->transfer_buffer_length &&
+ urb->status == 0))
+ urb->status = -EREMOTEIO;
+ }
+
/* When giving back the first URB in an Isochronous queue,
* reinitialize the QH's iso-related members for the next URB. */
- if (qh->type == USB_ENDPOINT_XFER_ISOC &&
+ else if (qh->type == USB_ENDPOINT_XFER_ISOC &&
urbp->node.prev == &qh->queue &&
urbp->node.next != &qh->queue) {
struct urb *nurb = list_entry(urbp->node.next,
--
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