diff options
| author | Phoenix Huang <phoenix@emc.com.tw> | 2021-11-07 22:00:03 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-26 11:58:33 +0100 |
| commit | 0534204713bc6e0ed47f717d66ecd053cb9f2c0f (patch) | |
| tree | 2bfc76749505ecb74427836ca9144c23b35a9ceb | |
| parent | 29f4189ec8e8c9074d63779009d5e73919193c50 (diff) | |
Input: elantench - fix misreporting trackpoint coordinates
commit be896bd3b72b44126c55768f14c22a8729b0992e upstream.
Some firmwares occasionally report bogus data from trackpoint, with X or Y
displacement being too large (outside of [-127, 127] range). Let's drop such
packets so that we do not generate jumps.
Signed-off-by: Phoenix Huang <phoenix@emc.com.tw>
Tested-by: Yufei Du <yufeidu@cs.unc.edu>
Link: https://lore.kernel.org/r/20210729010940.5752-1-phoenix@emc.com.tw
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/input/mouse/elantech.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index 7b942ee364b6..d5307b927378 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -435,6 +435,19 @@ static void elantech_report_trackpoint(struct psmouse *psmouse, case 0x16008020U: case 0x26800010U: case 0x36808000U: + + /* + * This firmware misreport coordinates for trackpoint + * occasionally. Discard packets outside of [-127, 127] range + * to prevent cursor jumps. + */ + if (packet[4] == 0x80 || packet[5] == 0x80 || + packet[1] >> 7 == packet[4] >> 7 || + packet[2] >> 7 == packet[5] >> 7) { + elantech_debug("discarding packet [%6ph]\n", packet); + break; + + } x = packet[4] - (int)((packet[1]^0x80) << 1); y = (int)((packet[2]^0x80) << 1) - packet[5]; |