Re: [REGRESSION] Right touchpad button disabled on Dell 7750

Takashi Iwai
2022-03-18T14:37:29Z

On Fri, 18 Mar 2022 15:06:55 +0100,
Benjamin Tissoires wrote:
>
> > > A couple of days ago another user with the same laptop (Dell Precision
> > > 7550 or 7750) emailed me to report the issue and I sent him a patch for
> > > testing.
> > >
> > > I he confirms that the patch works, I'll send it to the mailing list.
> > >
> > > I believe that your analysis of the regression is correct and I think
> > > that we'd need to add a quirk for the device.
> > >
> > > In case you want to have a look to the patch, I added it to this
> > > libinput [1] report.
> >
> > Great, I'll try to build and ask the reporter to test with the patch.
> >
>
> As noticed on the libinput bug, I think the patch is wrong (not by a lot).
> We should base the class on MT_CLS_WIN8, not MT_CLS_DEFAULT.
>
> The testers might say that it's working, but this might create some
> corner cases where it's not leading to more and more headaches with
> your users.

So is it like below? I'll build another kernel with that.

Thanks!

Takashi

-- 8< --
From: José Expósito <jose.exposito89@gmail.com>
Subject: [PATCH] HID: multitouch: fix Dell Precision 7550 and 7750 button type

The touchpad present in the Dell Precision 7550 and 7750 laptops
reports a HID_DG_BUTTONTYPE of type MT_BUTTONTYPE_CLICKPAD. However,
the device is not a clickpad, it is a touchpad with physical buttons.

In order to fix this issue, a quirk for the device was introduced in
libinput [1] [2] to disable the INPUT_PROP_BUTTONPAD property:

[Precision 7x50 Touchpad]
MatchBus=i2c
MatchUdevType=touchpad
MatchDMIModalias=dmi:*svnDellInc.:pnPrecision7?50*
AttrInputPropDisable=INPUT_PROP_BUTTONPAD

However, because of the change introduced in 37ef4c19b4 ("Input: clear
BTN_RIGHT/MIDDLE on buttonpads") the BTN_RIGHT key bit is not mapped
anymore breaking the device right click button.

In order to fix the issue, create a quirk for the device forcing its
button type to touchpad regardless of the value reported by the
firmware.

[1] https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/481
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1868789

[ modified MT_CLS_BUTTONTYPE_TOUCHPAD quirk bits to base on MT_CLS_WIN8
as suggested by Benjamin -- tiwai ]

Fixes: 37ef4c19b4 ("Input: clear BTN_RIGHT/MIDDLE on buttonpads")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
drivers/hid/hid-ids.h | 3 +++
drivers/hid/hid-multitouch.c | 20 ++++++++++++++++++++
2 files changed, 23 insertions(+)

--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -285,6 +285,9 @@

#define USB_VENDOR_ID_CIDC 0x1677

+#define USB_VENDOR_ID_CIRQUE_CORP 0x0488
+#define USB_DEVICE_ID_DELL_PRECISION_7X50 0x120A
+
#define USB_VENDOR_ID_CJTOUCH 0x24b8
#define USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0020 0x0020
#define USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0040 0x0040
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -71,6 +71,7 @@ MODULE_LICENSE("GPL");
#define MT_QUIRK_SEPARATE_APP_REPORT BIT(19)
#define MT_QUIRK_FORCE_MULTI_INPUT BIT(20)
#define MT_QUIRK_DISABLE_WAKEUP BIT(21)
+#define MT_QUIRK_BUTTONTYPE_TOUCHPAD BIT(22)

#define MT_INPUTMODE_TOUCHSCREEN 0x02
#define MT_INPUTMODE_TOUCHPAD 0x03
@@ -194,6 +195,7 @@ static void mt_post_parse(struct mt_devi
#define MT_CLS_WIN_8_FORCE_MULTI_INPUT 0x0015
#define MT_CLS_WIN_8_DISABLE_WAKEUP 0x0016
#define MT_CLS_WIN_8_NO_STICKY_FINGERS 0x0017
+#define MT_CLS_BUTTONTYPE_TOUCHPAD 0x0018

/* vendor specific classes */
#define MT_CLS_3M 0x0101
@@ -302,6 +304,15 @@ static const struct mt_class mt_classes[
MT_QUIRK_CONTACT_CNT_ACCURATE |
MT_QUIRK_WIN8_PTP_BUTTONS,
.export_all_inputs = true },
+ { .name = MT_CLS_BUTTONTYPE_TOUCHPAD,
+ .quirks = MT_QUIRK_ALWAYS_VALID |
+ MT_QUIRK_IGNORE_DUPLICATES |
+ MT_QUIRK_HOVERING |
+ MT_QUIRK_CONTACT_CNT_ACCURATE |
+ MT_QUIRK_STICKY_FINGERS |
+ MT_QUIRK_WIN8_PTP_BUTTONS |,
+ MT_QUIRK_BUTTONTYPE_TOUCHPAD,
+ .export_all_inputs = true },

/*
* vendor specific classes
@@ -1286,6 +1297,9 @@ static int mt_touch_input_configured(str
(app->buttons_count == 1))
td->is_buttonpad = true;

+ if (app->quirks & MT_QUIRK_BUTTONTYPE_TOUCHPAD)
+ td->is_buttonpad = false;
+
if (td->is_buttonpad)
__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

@@ -1875,6 +1889,12 @@ static const struct hid_device_id mt_dev
MT_USB_DEVICE(USB_VENDOR_ID_CHUNGHWAT,
USB_DEVICE_ID_CHUNGHWAT_MULTITOUCH) },

+ /* Cirque Corp (Dell Precision 7550 and 7750 touchpad) */
+ { .driver_data = MT_CLS_BUTTONTYPE_TOUCHPAD,
+ HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
+ USB_VENDOR_ID_CIRQUE_CORP,
+ USB_DEVICE_ID_DELL_PRECISION_7X50) },
+
/* CJTouch panels */
{ .driver_data = MT_CLS_NSMU,
MT_USB_DEVICE(USB_VENDOR_ID_CJTOUCH,