From 11db8173dbab7a94cf5ba5225fcedbfc0f3b7e54 Mon Sep 17 00:00:00 2001
From: Jason Gerecke <killertofu@gmail.com>
Date: Wed, 10 Oct 2018 13:40:26 -0700
Subject: [PATCH] HID: wacom: Work around HID descriptor bug in DTK-2451 and DTH-2452
Git-commit: 11db8173dbab7a94cf5ba5225fcedbfc0f3b7e54
Patch-mainline: v4.20-rc1
References: bsc#1051510

The DTK-2451 and DTH-2452 have a buggy HID descriptor which incorrectly
contains a Cintiq-like report, complete with pen tilt, rotation, twist, serial
number, etc. The hardware doesn't actually support this data but our driver
duitifully sets up the device as though it does. To ensure userspace has a
correct view of devices without updated firmware, we clean up this incorrect
data in wacom_setup_device_quirks.

We're also careful to clear the WACOM_QUIRK_TOOLSERIAL flag since its presence
causes the driver to wait for serial number information (via
wacom_wac_pen_serial_enforce) that never comes, resulting in
the pen being non-responsive.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Fixes: 8341720642 ("HID: wacom: Queue events with missing type/serial data for later processing")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hid/wacom_wac.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index e0a06be5ef5c..5dd3a8245f0f 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -3335,6 +3335,7 @@ static void wacom_setup_intuos(struct wacom_wac *wacom_wac)
 
 void wacom_setup_device_quirks(struct wacom *wacom)
 {
+	struct wacom_wac *wacom_wac = &wacom->wacom_wac;
 	struct wacom_features *features = &wacom->wacom_wac.features;
 
 	/* The pen and pad share the same interface on most devices */
@@ -3464,6 +3465,24 @@ void wacom_setup_device_quirks(struct wacom *wacom)
 
 	if (features->type == REMOTE)
 		features->device_type |= WACOM_DEVICETYPE_WL_MONITOR;
+
+	/* HID descriptor for DTK-2451 / DTH-2452 claims to report lots
+	 * of things it shouldn't. Lets fix up the damage...
+	 */
+	if (wacom->hdev->product == 0x382 || wacom->hdev->product == 0x37d) {
+		features->quirks &= ~WACOM_QUIRK_TOOLSERIAL;
+		__clear_bit(BTN_TOOL_BRUSH, wacom_wac->pen_input->keybit);
+		__clear_bit(BTN_TOOL_PENCIL, wacom_wac->pen_input->keybit);
+		__clear_bit(BTN_TOOL_AIRBRUSH, wacom_wac->pen_input->keybit);
+		__clear_bit(ABS_Z, wacom_wac->pen_input->absbit);
+		__clear_bit(ABS_DISTANCE, wacom_wac->pen_input->absbit);
+		__clear_bit(ABS_TILT_X, wacom_wac->pen_input->absbit);
+		__clear_bit(ABS_TILT_Y, wacom_wac->pen_input->absbit);
+		__clear_bit(ABS_WHEEL, wacom_wac->pen_input->absbit);
+		__clear_bit(ABS_MISC, wacom_wac->pen_input->absbit);
+		__clear_bit(MSC_SERIAL, wacom_wac->pen_input->mscbit);
+		__clear_bit(EV_MSC, wacom_wac->pen_input->evbit);
+	}
 }
 
 int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
-- 
2.16.4