On Thu, May 3, 2012 at 3:19 PM, Henrik Rydberg <rydberg@xxxxxxxxxxx> wrote: >> > 1) Add the devices in question back to the have_special_drivers list. >> >> Well... The device presents valid mouse and keyboard interface that >> should be handled by hid-generic. >> The behavior of this particular device is the following: >> - when 1 finger is in use, then it sends events over the mouse interface >> - when 2 fingers are present, it sends events over the multitouch interface >> - when you physically trigger the switch mode button, a keyboard >> appears and it sends key events over the keyboard interface, and >> eventually mouse events if you press the "mouse" key.... ;-) >> >> This crap is all inherited by the fact that Microsoft do not want to >> handle indirect touch, and the device maker found this solution to >> counter this. >> >> To sum up, adding it to the have_special_drivers driver list won't >> work as we need part of the device to be handled by hid-generic. > > So was this particular device never listed in have_special_drivers? No, and that's the way it should (not being part of have_special_driver). > >> > 2) Add the interface type to the group descision, which should >> > probably be done anyway. I have a patch in the pipe that, will send it >> > later today. >> >> A simpler solution consists in adding the macros HID_USB_MT_DEVICE(v, >> p) and HID_BLUETOOTH_MT_DEVICE(v, p) as you had introduced in a >> earlier patch (I don't know why it disappeared). > > No, the specific entries in the hid-multitouch device list matches any > group, so those defines were simplified away in the second version. disagree: a device can present several interface (because it has several "devices") and only those presenting Contact ID can and should be handled by hid-multitouch. Cypress for instance presents one interface for the multitouch layer, and one other for specific controls that are seen as a keyboard. However, in this particular case, I'm not sure we want to show this interface to the end user.... ;-) > >> The problem came out because: >> - hid-multitouch registered the triplet BUS_USB / VID / PID. >> - For each interface, it asks udev (or the kernel) which driver to >> use, and whatever .group was, it was always hid-multitouch that came >> out. >> >> So it's just safer to specify the group for all multitouch devices. > > This is still confusing. I thought the real problem was that the > non-mt interfaces do not match hid-generic. Solution 2) should take > care of that. What I don't understand is how those other interfaces > came to be handled by hid-generic before this patch, unless this > device was never listed in have_special_driver. The think is that they do match hid-generic (they get the group HID_GROUP_GENERIC). However they also match hid-multitouch (as hid-multitouch does not ask for a particular group). So, if hid-multitouch is loaded __before__ hid-generic, it will be given the device whatever the match with hid-generic. And again, yes it was never listed in have_special_driver. > > Are we talking about USB_DEVICE_ID_TOPSEED2_PERIPAD_701 here? yep - For consistency, I'd rather specifying the group for any devices. This because hid-multitouch can not handle other interfaces than multitouch one. Though the catchall is interesting in the sense that it may help us to hide unwanted interfaces. - For backward compatibility, we should adapt each device (currently, I only spotted this particular one) to decide if we need to catch the group or not. Jiri, any thought? Benjamin > > Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
