RE: [Qemu-devel] No cancel callback for usb-ohci

[Arnon Gilboa]

You may add a flag to USBPacket and raise it upon your
ohci_async_cancel_packet.
ohci_async_complete_packet will check this flag and do nothing if it is
up.
Am I missing something?

-----Original Message-----
From: address@hidden
[mailto:address@hidden On Behalf Of
Salil Bijur
Sent: Thursday, November 08, 2007 12:47 PM
To: address@hidden
Subject: Re: [Qemu-devel] No cancel callback for usb-ohci

Hi Arnon,

On Nov 8, 2007 3:28 PM, Arnon Gilboa <address@hidden> wrote:
> Seems like an ugly bug (common also to uhci), which I haven't noticed 
> before.
> I guess this scenario has never happened to me. Can you please 
> describe it?

What I'm trying to do is to prevent the lag caused by the USBDEVFS_BULK
ioctl and instead send the bulk transfers asynchronously using the
USBDEVFS_SUBMITURB ioctl. I'm taking the help of the patch you had sent
for isochronous packets.

This scenario occurs when the usb bluetooth dongle is added to the linux
guest and its interface is brought up.

> Call usb_defer_packet with cancel_cb which flags the packet, so the 
> following usb_packet_complete will be ignored.

To call usb_defer_packet, there needs to be a callback function like the
usb_msd_cancel_io function used in hw/usb-msd.c:
usb_defer_packet(p, usb_msd_cancel_io, s);

There doesn't seem to be a similar cancel_cb callback for ohci. An empty
stub function prevents this crash, but should it be doing more stuff
like the msd one does?

Salil

>
>
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On Behalf 
> Of Salil Bijur
> Sent: Thursday, November 08, 2007 8:51 AM
> To: address@hidden
> Subject: [Qemu-devel] No cancel callback for usb-ohci
>
> Hello,
>
> There is a call to the function usb_cancel_packet in hw/usb-ohci.c.
> However, there is no cancel_cb callback registered for the
> ohci->usb_packet resulting in a segmentation fault.
>
> Are there any plans to implement this cancel callback?
>
> Thanks,
> Salil
>
>
>
>
>