From e7e7c360fb07020b24652843aec442325baad0ce Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 13 Jul 2007 15:46:29 -0400 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/uhci-q.c | 59 +++++++++++++++++++++++++-------------- 1 file changed, 38 insertions(+), 21 deletions(-) diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index 4aed305982ec..3bb908ca38e9 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, -- 2.30.2