linux-kernel - [PATCH 2/3] Input: wacom - Don't discard bits from upper byte of pressure value

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 26 Feb 2014 14:38:15 -0800
From:	Carl Worth <cworth@...rth.org>
To:	Ping Cheng <pingc@...om.com>
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Carl Worth <cworth@...rth.org>
Subject: [PATCH 2/3] Input: wacom - Don't discard bits from upper byte of pressure value

The mask here previously discarded all but one bit of data from the
upper byte of the pressure value. That would be correct for a tablet
with at most 512 pressure values, but is incorrect for a tablet with
1024 or more pressure values.

We can support as many tablets as possible by simply not discarding
any of the bits from this byte.

Signed-off-by: Carl Worth <cworth@...rth.org>
---
 drivers/input/tablet/wacom_wac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index 4958081..563f197 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -1037,7 +1037,7 @@ static int wacom_tpc_pen(struct wacom_wac *wacom)
 		input_report_key(input, BTN_STYLUS2, data[1] & 0x10);
 		input_report_abs(input, ABS_X, le16_to_cpup((__le16 *)&data[2]));
 		input_report_abs(input, ABS_Y, le16_to_cpup((__le16 *)&data[4]));
-		pressure = ((data[7] & 0x01) << 8) | data[6];
+		pressure = (data[7] << 8) | data[6];
 		if (pressure < 0)
 			pressure = features->pressure_max + pressure + 1;
 		input_report_abs(input, ABS_PRESSURE, pressure);
-- 
1.9.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/