Hi Allen,

On Tue, Jun 21, 2016 at 11:20 AM, Allen Hung [off-list ref] wrote:

Hi Benjamin,

On 01/04/2016 04:35 PM, Benjamin Tissoires wrote:

quoted

Hi Allen,

On Mon, Dec 21, 2015 at 10:45 AM, Allen Hung [off-list ref] wrote:

quoted

On 12/18/2015 05:52 AM, Benjamin Tissoires wrote:

quoted

On Thu, Nov 26, 2015 at 3:21 PM, Jiri Kosina [off-list ref] wrote:

quoted

On Fri, 20 Nov 2015, Allen Hung wrote:

quoted

The usage Confidence is mandary to Windows Precision Touchpad devices. The
appearance of this usage is checked in hidinput_connect but the quirk
MT_QUIRK_VALID_IS_CONFIDENCE is not applied to device accordingly.
Apply this quirk and also remove quirk MT_QUIRK_ALWAYS_VALID to enable palm
rejection for the WIN 8 touchpad devices which have implemented usage
Confidence in its input reports.

Tested on Dell XPS 13 laptop.

Signed-off-by: Allen Hung <redacted>

Applied to for-4.5/multitouch. Thanks,

Allen, looks like the Dell XPS13 2015 (or was it the 2014?) has
problems with your patch:
https://bugzilla.redhat.com/show_bug.cgi?id=1292583 (we backported
this change in the Fedora kernel 4.2.7).

Would you mind checking that this patch does not create regressions on
older series of laptops?

Thanks in advance.

Cheers,
Benjamin

Hi Benjamin,

It looks like a XPS13 2014 but I can confirm this with my colleagues who are in charge of this product line. I don't mind checking this patch with more older series of laptops. I will do it and let you know the status. Should I also test the machines with Fedora 23, or just go with Ubuntu OS? The XPS machines are shipped with Ubuntu.
Btw, the issue reporter said she/he cannot reproduce the issue (posted on Dec. 18).

[Sorry for the late answer, but you guessed the holiday season did not help :)]

I think I'll just ask the reporter to confirm he can not reproduce and
then close the downstream bug.
Unless other people complains, I think we can just keep the current
state and wait :)

Cheers,
Benjamin

My this patch 25a84db15b3f3a24d3ea7d2baf90693bcff34b0c (HID: multitouch: enable
palm rejection if device implements confidence usage) brings side effect as
someone reported it on https://bugzilla.kernel.org/show_bug.cgi?id=112791
My fix is attached in the thread and please have a look at it and my reply in
comment #5 as the root cause.
Let me try to explain my fix here - the quirk MT_QUIRK_VALID_IS_CONFIDENCE
is implemented in hid-multitouch and I see it was only applied to some
particular touchpad devices (see my list in the end) before my earlier patch
applies it to Windows 8 precision touchpad. I believe the quirk is working
very well for the devices in list, and it must have some stories behind that
made the quirk designed in this way - simply dropped the reports with
[confidence = 0].
However, this quirk isn't working very properly for the Win8 precise touchpad.
I think when a touch is initially detected as finger then
later detected as a palm, the driver has to send the latter detections
to input/mt as calling input_mt_report_slot_state(input, MT_TOOL_FINGER,
active=0). In order not to break the devices in list, I add a new quirk
MT_QUIRK_CONFIDENCE to do the work. Please provide your comments :)

Device list:
MT_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M1968)
MT_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M2256)
MT_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M3266)
MT_USB_DEVICE(USB_VENDOR_ID_ASUS, USB_DEVICE_ID_ASUS_T91MT)
MT_USB_DEVICE(USB_VENDOR_ID_ASUS, USB_DEVICE_ID_ASUSTEK_MULTITOUCH_YFO)
MT_USB_DEVICE(USB_VENDOR_ID_TURBOX, USB_DEVICE_ID_TURBOX_TOUCHSCREEN_MOSART)
MT_USB_DEVICE(USB_VENDOR_ID_QUANTA,     USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3001)
MT_USB_DEVICE(USB_VENDOR_ID_STANTUM_STM, USB_DEVICE_ID_MTP_STM)

I was discussing with Synaptics about that last week, and I was
planning on working on it this week. Looks like you got the patch
ready before me :)
I *think* the patch is valid, and should be carried in upstream and in
stable. I'd like to have a further look at it once you submit it
however before giving my rev-by.

Regarding the device list you provided, yes those devices should
reject the touch when the confidence bit is not set. These were
Windows 7 touchscreen and the spec was not very clear and we had to
tweak the code on a per-device basis.

I think I also have a few pending patches for hid-multitouch, but your
patch might supersede those.

Cheers,
Benjamin