Hi, On 02/13/2013 10:58 AM, Kustaa Nyholm wrote: > On 12.2.2013 12.29, "Hans de Goede" <hdego...@redhat.com> wrote: > <snip> >> On 02/12/2013 12:54 AM, Pete Batard wrote: >>> >>> Personally, the first thing I want out of hotplug from a libusbx/Windows >>> standpoint is to provide applications with the ability to notify users > <snip> >> >> We can simply add: >> >> LIBUSB_HOTPLUG_EVENT_DRIVERLESS_DEVICE_ARRIVED >> LIBUSB_HOTPLUG_EVENT_DRIVERLESS_DEVICE_LEFT > > Why is necessary or beneficial to have different events for > device plug in/out for driverless devices?
To detect transitions between the 2 states, ie a device gets plugged in, windows loads the standard driver for it, so from libusb pov it is driverless (as it does not have a driver which allows its use in libusb) this generates a LIBUSB_HOTPLUG_EVENT_DRIVERLESS_DEVICE_ARRIVED Some apps may respond to this by uninstalling the standard driver and attaching a libusb usable driver, ie the winusb driver, then the following 2 events are generated: LIBUSB_HOTPLUG_EVENT_DRIVERLESS_DEVICE_LEFT LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED Note that this very closely matches what exactly happens, when you uninstall the standard driver, windows will report this as the device having go away. And when you install the other driver it will report this as a new device being available. > In my thinking weather there is a driver or not is > logically a property of libusb_device and should > be queried from that handle and result in corresponding > error (LIBUSB_ERROR_NO_DRIVER) if passed to libusb_open(). Apps which are actually interested in this will want an event on the transitions from driverless to non-driverless too, so that they will know that the windows-device-manager is done with the driver installation. Regards, Hans ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
