From c8e5e170d97ab10cf4dd1dfee9172a3856c3519b Mon Sep 17 00:00:00 2001 From: Jason Gerecke Date: Mon, 28 Oct 2024 10:39:14 -0700 Subject: [PATCH] HID: wacom: Interpret tilt data from Intuos Pro BT as signed values commit 49a397ad24ee5e2c53a59dada2780d7e71bd3f77 upstream. The tilt data contained in the Bluetooth packets of an Intuos Pro are supposed to be interpreted as signed values. Simply casting the values to type `char` is not guaranteed to work since it is implementation- defined whether it is signed or unsigned. At least one user has noticed the data being reported incorrectly on their system. To ensure that the data is interpreted properly, we specifically cast to `signed char` instead. Link: https://github.com/linuxwacom/input-wacom/issues/445 Fixes: 4922cd26f03c ("HID: wacom: Support 2nd-gen Intuos Pro's Bluetooth classic interface") CC: stable@vger.kernel.org # 4.11+ Signed-off-by: Jason Gerecke Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/wacom_wac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index e083e21fe742..0ec75848ca80 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -1394,9 +1394,9 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) rotation -= 1800; input_report_abs(pen_input, ABS_TILT_X, - (char)frame[7]); + (signed char)frame[7]); input_report_abs(pen_input, ABS_TILT_Y, - (char)frame[8]); + (signed char)frame[8]); input_report_abs(pen_input, ABS_Z, rotation); input_report_abs(pen_input, ABS_WHEEL, get_unaligned_le16(&frame[11]));