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Date:   Sun, 17 Sep 2023 16:18:43 +0000
To:     Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Henrik Rydberg <rydberg@bitmath.org>
From:   Rahul Rameshbabu <sergeantsagara@protonmail.com>
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        Rahul Rameshbabu <sergeantsagara@protonmail.com>,
        Rain <rain@sunshowers.io>
Subject: [PATCH] HID: multitouch: Add required quirk for Synaptics 0xcd7e device
Message-ID: <20230917161802.39716-1-sergeantsagara@protonmail.com>
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Register the Synaptics device as a special multitouch device with certain
quirks that may improve usability of the touchpad device.

Reported-by: Rain <rain@sunshowers.io>
Closes: https://lore.kernel.org/linux-input/2bbb8e1d-1793-4df1-810f-cb01373=
41ff4@app.fastmail.com/
Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com>
---

Notes:
    Theory:
   =20
      I think the Synaptics device in the related email to the linux-input
      mailing list requires certain quirks like MT_QUIRK_HOVERING to correc=
tly
      reconfigure the distance configuration for multitouch events. This mi=
ght
      explain why light touches were not registered originally when
      MT_CLS_DEFAULT was used by default for the device. Would like to have
      this patch tested before being merged. A Tested-by: git trailer can t=
hen
      be appended.

 drivers/hid/hid-multitouch.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 521b2ffb4244..8db4ae05febc 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -2144,6 +2144,10 @@ static const struct hid_device_id mt_devices[] =3D {
 =09=09=09USB_DEVICE_ID_MTP_STM)},
=20
 =09/* Synaptics devices */
+=09{ .driver_data =3D MT_CLS_WIN_8_FORCE_MULTI_INPUT,
+=09=09HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
+=09=09=09USB_VENDOR_ID_SYNAPTICS, 0xcd7e) },
+
 =09{ .driver_data =3D MT_CLS_WIN_8_FORCE_MULTI_INPUT,
 =09=09HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
 =09=09=09USB_VENDOR_ID_SYNAPTICS, 0xce08) },
--=20
2.40.1