Thanks Mathis for these suggestions, i'm going to try it, and let you
know the results.
i hope you have a nice rest.
Gustavo.
On Thu, Dec 18, 2014 at 2:12 PM, Mathias Nyman
<mathias.nyman@xxxxxxxxxxxxxxx> wrote:
> Hi
>
> On 18.12.2014 13:49, Gustavo Duarte wrote:
>> Mathias /Guys,
>>
>> I got the debug log of the xhci_hcd module, during the communication
>> with the robot kit (Lego brick).
>>
>> Attached are two files:
>>
>> brick-boot.log:
>> The brick is connected to USB port, and press switch ON button.
>>
>> upload.log:
>> The brick is already ON, and start the uploading of an application
>> code from PC -> Brick, the uploading procedure never finished.
>>
>> I don't know so much about usb communications, but seeing these file
>> logs, I didn't see any estrange message.
>>
>> What do you think, can you see some clue there ?
>
> Looks like it first finds a mismatch in max packet size after device is
> addressed, xhci tries to re-configure the endpoint to match the new
> maxpacket size. It says it succeeds but immediately after that halts the
> endpoint. After this we see most of the usb transfers cancelled.
>
> Things to try:
>
> - use old style enumeration, before pluging in your device do:
> 'echo y > /sys/module/usbcore/parameters/old_scheme_first'
>
> - use 3.18 kernel, it has fixes for misbehaving halted control endpoints
>
> - hack the xhci code and remove setting the new maxpacket size, and see if
> it makes a difference.
> Do a codechange like this, (copy-pasted diff), and rebuild:
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 5be1bff..2778c37 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -1370,7 +1370,7 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
> /* Check to see if the max packet size for the default control
> * endpoint changed during FS device enumeration
> */
> - if (urb->dev->speed == USB_SPEED_FULL) {
> + if (urb->dev->speed == USB_SPEED_FULL && 0) {
> ret = xhci_check_maxpacket(xhci, slot_id,
> ep_index, urb);
> if (ret < 0) {
>
> I'll be away until 5. Jan on vacation, trying not to read emails
>
>
> -Mathias
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