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| author | Phoenix Huang <phoenix@emc.com.tw> | 2021-11-07 22:00:03 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2021-11-09 22:22:43 -0800 |
| commit | be896bd3b72b44126c55768f14c22a8729b0992e (patch) | |
| tree | a49f6768224c13a53fd3834207843a7da702d2fd /drivers | |
| parent | 6e4860410b828f8576c0c003d412fcf8a7d433f9 (diff) | |
| download | linux-be896bd3b72b44126c55768f14c22a8729b0992e.tar.bz2 | |
Input: elantench - fix misreporting trackpoint coordinates
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>
Diffstat (limited to 'drivers')
| -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 2d0bc029619f..956d9cd34796 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -517,6 +517,19 @@ 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]; |