[argyllcms] Re: HID issue with libusb on Huey
- From: "Frédéric Crozat" <fred@xxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Mon, 17 Dec 2007 07:22:51 +0100
On Dec 17, 2007 1:24 AM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:
> Frédéric Crozat wrote:
>
> > What distribution and what kernel version are you using ?
>
> I'm using WhiteBox 4 on an old piece of hardware and I updated
> it recently. The kernel is 2.6.9-55.EL
Wow and I thought I know a lot of distro :)
More seriously, you should try a more recent linux kernel, USB stack
has evolved a lot since 2.6.9 (even if it is patched in WB).
> > I've also tested when usbhid doesn't handle the device and
> > USBDEVFS_IOCTL is failing with the same error.
>
> It sounds like some change in the USB driver is causing
> this to fail.
>
> I notice that the IOCTL definitions are rather loosely
> connected to the user mode code - it's not
> like there is a .h file to glue things together with
> symbolic definitions, so it all depends on certain
> magic numbers not changing:
>
> #define IOCTL_USB_DISCONNECT _IO('U', 22)
>
> int usb_detach_kernel_driver_np(usb_dev_handle *dev, int interface)
> {
> struct usb_ioctl command;
> int ret;
>
> command.ifno = interface;
> command.ioctl_code = IOCTL_USB_DISCONNECT;
> command.data = NULL;
>
> ret = ioctl(dev->fd, IOCTL_USB_IOCTL, &command);
> if (ret)
> USB_ERROR_STR(-errno, "could not detach kernel driver from interface %d:
> %s",
> interface, strerror(errno));
>
> return 0;
> }
>
> Short of being able to trace exactly why the driver is rejecting
> the IOCTL, the usual procedure is to play around with the call
> (when it's called, what parameters it has), and see if one can
> stumble on a combination that works :-(
I'll try to patch our strace with a usbdevfs patch to display
parameters used (I've seen such patch floating around). And I'll ask
our kernel hackers at Mandriva if they have a clue.
--
Frederic Crozat
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