linux-kernel - [34-longterm 116/196] Input: elantech - discard the first 2 positions on some firmwares

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:	Mon, 12 Mar 2012 20:20:29 -0400
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	stable@...nel.org, linux-kernel@...r.kernel.org
Cc:	stable-review@...nel.org,
	Éric Piel <E.A.B.Piel@...elft.nl>,
	Éric Piel <eric.piel@...mplin-utc.net>,
	Dmitry Torokhov <dtor@...l.ru>,
	Paul Gortmaker <paul.gortmaker@...driver.com>
Subject: [34-longterm 116/196] Input: elantech - discard the first 2 positions on some firmwares

From: Éric Piel <E.A.B.Piel@...elft.nl>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 7f29f17b57255b6395046805a98bc663ded63fb8 upstream.

According to the Dell/Ubuntu driver, what was previously observed as
"jumpy cursor" corresponds to the hardware sending incorrect data for
the first two reports of a one touch finger. So let's use the same
workaround as in the other driver. Also, detect another firmware
version with the same behaviour, as in the other driver.

Signed-off-by: Éric Piel <eric.piel@...mplin-utc.net>
Signed-off-by: Dmitry Torokhov <dtor@...l.ru>
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
 drivers/input/mouse/elantech.c |   21 ++++++++++-----------
 drivers/input/mouse/elantech.h |    7 ++++---
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 4400369..a0c19c2 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -183,7 +183,6 @@ static void elantech_report_absolute_v1(struct psmouse *psmouse)
 	struct elantech_data *etd = psmouse->private;
 	unsigned char *packet = psmouse->packet;
 	int fingers;
-	static int old_fingers;
 
 	if (etd->fw_version < 0x020000) {
 		/*
@@ -201,10 +200,13 @@ static void elantech_report_absolute_v1(struct psmouse *psmouse)
 	}
 
 	if (etd->jumpy_cursor) {
-		/* Discard packets that are likely to have bogus coordinates */
-		if (fingers > old_fingers) {
+		if (fingers != 1) {
+			etd->single_finger_reports = 0;
+		} else if (etd->single_finger_reports < 2) {
+			/* Discard first 2 reports of one finger, bogus */
+			etd->single_finger_reports++;
 			elantech_debug("elantech.c: discarding packet\n");
-			goto discard_packet_v1;
+			return;
 		}
 	}
 
@@ -236,9 +238,6 @@ static void elantech_report_absolute_v1(struct psmouse *psmouse)
 	}
 
 	input_sync(dev);
-
- discard_packet_v1:
-	old_fingers = fingers;
 }
 
 /*
@@ -734,14 +733,14 @@ int elantech_init(struct psmouse *psmouse)
 	etd->capabilities = param[0];
 
 	/*
-	 * This firmware seems to suffer from misreporting coordinates when
+	 * This firmware suffers from misreporting coordinates when
 	 * a touch action starts causing the mouse cursor or scrolled page
 	 * to jump. Enable a workaround.
 	 */
-	if (etd->fw_version == 0x020022) {
-		pr_info("elantech.c: firmware version 2.0.34 detected, "
+	if (etd->fw_version == 0x020022 || etd->fw_version == 0x020600) {
+		pr_info("elantech.c: firmware version 2.0.34/2.6.0 detected, "
 			"enabling jumpy cursor workaround\n");
-		etd->jumpy_cursor = 1;
+		etd->jumpy_cursor = true;
 	}
 
 	if (elantech_set_absolute_mode(psmouse)) {
diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index ac57bde..aa4aac5 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -100,10 +100,11 @@ struct elantech_data {
 	unsigned char reg_26;
 	unsigned char debug;
 	unsigned char capabilities;
-	unsigned char paritycheck;
-	unsigned char jumpy_cursor;
+	bool paritycheck;
+	bool jumpy_cursor;
 	unsigned char hw_version;
-	unsigned int  fw_version;
+	unsigned int fw_version;
+	unsigned int single_finger_reports;
 	unsigned char parity[256];
 };
 
-- 
1.7.9.3

--
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/