From 2cc08800a6b9fcda7c7afbcf2da1a6e8808da725 Mon Sep 17 00:00:00 2001
From: Jason Gerecke <jason.gerecke@wacom.com>
Date: Wed, 24 Apr 2019 15:12:57 -0700
Subject: [PATCH] HID: wacom: Don't set tool type until we're in range
Git-commit: 2cc08800a6b9fcda7c7afbcf2da1a6e8808da725
Patch-mainline: v5.2 or v5.2-rc5 (next release)
References: bsc#1051510

The serial number and tool type information that is reported by the tablet
while a pen is merely "in prox" instead of fully "in range" can be stale
and cause us to report incorrect tool information. Serial number, tool
type, and other information is only valid once the pen comes fully in range
so we should be careful to not use this information until that point.

In particular, this issue may cause the driver to incorectly report
BTN_TOOL_RUBBER after switching from the eraser tool back to the pen.

Fixes: a48324de6d4d ("HID: wacom: Bluetooth IRQ for Intuos Pro should handle prox/range")
Cc: <stable@vger.kernel.org> # 4.11+
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hid/wacom_wac.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 747730d32ab6..4c1bc239207e 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1236,13 +1236,13 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom)
 		/* Add back in missing bits of ID for non-USI pens */
 		wacom->id[0] |= (wacom->serial[0] >> 32) & 0xFFFFF;
 	}
-	wacom->tool[0]   = wacom_intuos_get_tool_type(wacom_intuos_id_mangle(wacom->id[0]));
 
 	for (i = 0; i < pen_frames; i++) {
 		unsigned char *frame = &data[i*pen_frame_len + 1];
 		bool valid = frame[0] & 0x80;
 		bool prox = frame[0] & 0x40;
 		bool range = frame[0] & 0x20;
+		bool invert = frame[0] & 0x10;
 
 		if (!valid)
 			continue;
@@ -1251,9 +1251,24 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom)
 			wacom->shared->stylus_in_proximity = false;
 			wacom_exit_report(wacom);
 			input_sync(pen_input);
+
+			wacom->tool[0] = 0;
+			wacom->id[0] = 0;
+			wacom->serial[0] = 0;
 			return;
 		}
+
 		if (range) {
+			if (!wacom->tool[0]) { /* first in range */
+				/* Going into range select tool */
+				if (invert)
+					wacom->tool[0] = BTN_TOOL_RUBBER;
+				else if (wacom->id[0])
+					wacom->tool[0] = wacom_intuos_get_tool_type(wacom->id[0]);
+				else
+					wacom->tool[0] = BTN_TOOL_PEN;
+			}
+
 			input_report_abs(pen_input, ABS_X, get_unaligned_le16(&frame[1]));
 			input_report_abs(pen_input, ABS_Y, get_unaligned_le16(&frame[3]));
 
-- 
2.16.4