[PATCH] Input: sentelic - filtering out erratic movement

[Tai-hwa Liang <avatar@sentelic.com>]

It turns out that certain hardware sometime generates unexpected movement
during normal operation. This patch tries to filter out these erratic
movements which will cause unexpected cursor jumping to the top-left corner.

Bugzilla:	https://bugzilla.kernel.org/show_bug.cgi?id=43197
Reported-by:	Aleksey Spiridonov <leks13@leks13.ru>
Tested-by:	Aleksey Spiridonov <leks13@leks13.ru>
Signed-off-by: Tai-hwa Liang <avatar@sentelic.com>
---
 drivers/input/mouse/sentelic.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/input/mouse/sentelic.c b/drivers/input/mouse/sentelic.c
index 3f5649f..48967a4 100644
--- a/drivers/input/mouse/sentelic.c
+++ b/drivers/input/mouse/sentelic.c
@@ -721,6 +721,14 @@ static psmouse_ret_t fsp_process_byte(struct psmouse *psmouse)
 
 	switch (psmouse->packet[0] >> FSP_PKT_TYPE_SHIFT) {
 	case FSP_PKT_TYPE_ABS:
+		if ((packet[0] == 0x48 || packet[0] == 0x49) &&
+		    packet[1] == 0 && packet[2] == 0) {
+			/*
+			 * filtering out erratic movement which will cause
+			 * unexpected cursor jumping to top-left corner
+			 */
+			packet[3] &= 0xf0;
+		}
 		abs_x = GET_ABS_X(packet);
 		abs_y = GET_ABS_Y(packet);
 
-- 
1.7.10