Re: [PATCH v2] HID: multitouch: Fetch feature reports on demand for Win8 devices

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Wed, Oct 07, 2015 at 06:12:42PM -0700, Andrew Duggan wrote:
> I can confirm that it is working on the Dell XPS 13 and the buttonpad
> property is set correctly. However, I also tried it on an older non
> production precision touchpad and it didn't work. It reports that it fails
> to fetch feature 8 and then doesn't report any input. I'm concerned that
> some of the early PTPs in some Dell and Acer systems might not work with
> this change. I'll test this tomorrow on a few more systems to see if the
> problem is isolated to just this one non production touchpad.

Thanks for testing.

> [ 2969.222125] usb 1-1: New USB device found, idVendor=06cb, idProduct=2393
> [ 2969.222128] usb 1-1: New USB device strings: Mfr=0, Product=2,
> SerialNumber=0
> [ 2969.222130] usb 1-1: Product: Synaptics T Pad V 01.31
> [ 2974.223578] hid-multitouch 0003:06CB:2393.0008: failed to fetch feature 8
> [ 2979.226037] hid-multitouch 0003:06CB:2393.0008: failed to fetch feature 8
> [ 2979.226137] input: Synaptics T Pad V 01.31 UNKNOWN as /devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0/0003:06CB:2393.0008/input/input34
> [ 2979.226431] hid-multitouch 0003:06CB:2393.0008: input,hiddev0,hidraw2:
> USB HID v1.11 Mouse [Synaptics T Pad V 01.31] on usb-0000:00:14.0-1/input0

Without the patch is it successfully retrieving feature 8?

It may be that it has HID_QUIRK_NO_INIT_REPORTS set via quirks in usbhid
which causes the driver to fetch the report in mt_feature_mapping() and
previously it did not do that.