Re: HID bus

[Anssi Hannula <anssi.hannula@gmail.com>]

Jiri Slaby wrote:
> Hmm, I must admit, I didn't know how exactly autoloading works. On suse,
> at least, module aliases are used. So autoloading works for me after this
> patch and slight modifications of the previous patches. The pro of this
> is that it's in-kernel modification of modpost phase.

Indeed in current systems udev uses module aliases for autoloading.

> --
> 
> Generate aliases for usb hid device modules to support autoloading.
> 
> Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
[...]
> +/* Looks like: usb */

Looks like: "usb:vNpNd*dc*dsc*dp*ic3isc*ip*"

> +static int do_hid_usb_entry(const char *filename,
> +			     struct hid_device_id *id, char *alias)
> +{
> +	__u16 v = TO_NATIVE((__u16)id->vendor);
> +	__u16 p = TO_NATIVE((__u16)id->product);
> +
> +	strcpy(alias, "usb:");
> +	ADD(alias, "v", id->vendor != HID_ANY_ID, v);
> +	ADD(alias, "p", id->product != HID_ANY_ID, p);
> +
> +	sprintf(alias + strlen(alias), "d*dc*dsc*dp*ic%02Xisc*ip*",
> +			USB_INTERFACE_CLASS_HID);
> +
> +	return 1;
> +}

Oh, so we create a normal usb modalias entry anyway, not a custom
'usbhid:' one.

Why not just do something like

#define HID_DEVICE(vend, dev) \
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
		       USB_DEVICE_ID_MATCH_INT_CLASS, \
	.idVendor = (vend), \
	.idProduct = (prod), \
	.bInterfaceClass = USB_INTERFACE_CLASS_HID
(see linux/usb.h)

and use USB hotplugging?

Or do we plan to match against something else as well, such as hid
reports or something?

-- 
Anssi Hannula