Re: [PATCH] usb-host: workaround libusb bug

[Gerd Hoffmann]

On Wed, Sep 02, 2020 at 03:31:46PM +0100, Alex Bennée wrote:
> 
> Gerd Hoffmann <kraxel@redhat.com> writes:
> 
> >> > +#include <linux/usbdevice_fs.h>
> >
> >> > +        int rc = ioctl(hostfd, USBDEVFS_GET_SPEED, NULL);
> >> 
> >> This (further) breaks a bunch of the Travis jobs - I assume because libusb 
> >> doesn't
> >> always have this symbol:
> >> 
> >>   ../hw/usb/host-libusb.c:954:32: error: ‘USBDEVFS_GET_SPEED’ undeclared 
> >> (first use in this function)
> >
> > It isn't libusb, it is the kernel (linux/usbdevice_fs.h).
> >
> > /me checks git ...
> > Added in 4.13, so available for quite a while.
> > I guess that is the prehistoric ubuntu version travis has?
> >
> > Given that we only need that workaround with rather new libusb versions
> > (which have libusb_wrap_sys_device() support) which most likely isn't
> > present in that old ubuntu version we can probably just do this:
> >
> > diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
> > index 08604f787fdf..c25102f3aca1 100644
> > --- a/hw/usb/host-libusb.c
> > +++ b/hw/usb/host-libusb.c
> > @@ -942,7 +942,7 @@ static int usb_host_open(USBHostDevice *s, 
> > libusb_device *dev, int hostfd)
> >      usb_host_ep_update(s);
> >  
> >      libusb_speed = libusb_get_device_speed(dev);
> > -#ifdef CONFIG_LINUX
> > +#if LIBUSB_API_VERSION >= 0x01000107 && defined(CONFIG_LINUX)
> >      if (hostfd && libusb_speed == 0) {
> >          /*
> >           * Workaround libusb bug: libusb_get_device_speed() does not
> 
> That works. Do you want to include that in your next PR or send a patch
> for me to include in my testing/next PR?

Patch is on the list already:
20200902081445.3291-1-kraxel@redhat.com/">https://patchwork.ozlabs.org/project/qemu-devel/patch/20200902081445.3291-1-kraxel@redhat.com/

Feel free to include it in testing pull.

take care,
  Gerd