From: Phoenix Huang phoenix@emc.com.tw
stable inclusion from stable-5.10.80 commit 8c341d11c8bd366791cacfbf96608de905607fde bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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 Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/input/mouse/elantech.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index e0e53a9a816f..4357d30c15c5 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];