On Thu, 21 Mar 2002, Johannes Erdfelt wrote:
> > uhci.c: 3440: host controller process error. something bad happened
>
> This is what I was looking for.
I'm getting exactly the same message with 2.5.7 when using irda-usb with
uhci (but not with usb-uhci). And the host locks solid, not even reacting
to any SysRq - but that's apparently not uhci's fault.
What IMHO is an uhci problem however, is the special handling for
USB_ZERO_PACKET: Looks like some typo, because I don't believe it's a good
idea to send TD with bogus MaxLen field to the device ;-)
Furthermore, the decision when to add a zero-packet didn't cover all
details.
The patch below vs. 2.5.7 fixes (hope so) these issues. At least it makes
the HCPE dissappear. irda-usb still isn't all that happy with it (in
contrast to my private driver using USB_ZERO_PACKET as well) - but that's
something to go on with Jean.
Johannes, is this ok with you?
Martin
----------------------------------------
--- linux-2.5.7/drivers/usb/uhci.c Sun Mar 10 03:45:21 2002
+++ v2.5.7-md/drivers/usb/uhci.c Sun Mar 24 23:20:35 2002
@@ -1270,14 +1270,21 @@
usb_pipeout(urb->pipe));
} while (len > 0);
- if (usb_pipeout(urb->pipe) && (urb->transfer_flags & USB_ZERO_PACKET) &&
- urb->transfer_buffer_length) {
+ /* USB_ZERO_PACKET means adding a 0-length packet, if
+ * direction is OUT and the transfer_length was an
+ * exact multiple of maxsze, hence
+ * (len = transfer_length - N * maxsze) == 0
+ * however, if transfer_length==0, the zero packet
+ * was already prepared above.
+ */
+ if ((urb->transfer_flags&USB_ZERO_PACKET) && usb_pipeout(urb->pipe)
+ && len==0 && urb->transfer_buffer_length>0) {
td = uhci_alloc_td(uhci, urb->dev);
if (!td)
return -ENOMEM;
uhci_add_td_to_urb(urb, td);
- uhci_fill_td(td, status, destination | UHCI_NULL_DATA_SIZE |
+ uhci_fill_td(td, status, destination | (UHCI_NULL_DATA_SIZE<<21) |
(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE),
data);
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