libusb20 api

Hans Petter Selasky hselasky at c2i.net
Tue Sep 22 16:38:06 UTC 2009


On Tuesday 22 September 2009 17:40:48 Hans Petter Selasky wrote:
> On Tuesday 22 September 2009 00:38:46 Trevor Blackwell wrote:
> > This always fails:
> >
> >        char devname[256];
> >        if (libusb20_dev_get_iface_desc(pdev, n, devname,
> > sizeof(devname))) break;
> >
> > while this works:
> >
> >        char devname[128];
> >        if (libusb20_dev_get_iface_desc(pdev, n, devname,
> > sizeof(devname))) break;
> >
> > Because this function takes a uint8_t for length:
> >
> > <libusb20_ugen20.c:851>:
> > static int
> > ugen20_dev_get_iface_desc(struct libusb20_device *pdev,
> >      uint8_t iface_index, char *buf, uint8_t len)
> >
> > even though the kernel ioctl structure has a 16-bit length.
> >
> > Hans, why not just use size_t for such arguments?
>
> Your point is valid. Currently USB string descriptors are always limited to
> 255 bytes. Setting up a larger buffer does not make sense.
>
> I will see what I can do.
>

s/string/interface/

> --HPS



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