[PATCH 5.4 04/34] Input: goodix - fix spurious key release events

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Dmitry Mastykin <dmastykin@astralinux.ru>

commit 24ef83f6e31d20fc121a7cd732b04b498475fca3 upstream.

The goodix panel sends spurious interrupts after a 'finger up' event,
which always cause a timeout.
We were exiting the interrupt handler by reporting touch_num == 0, but
this was still processed as valid and caused the code to use the
uninitialised point_data, creating spurious key release events.

Report an error from the interrupt handler so as to avoid processing
invalid point_data further.

Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20200316075302.3759-2-dmastykin@astralinux.ru
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/input/touchscreen/goodix.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -335,7 +335,7 @@ static int goodix_ts_read_input_report(s
 	 * The Goodix panel will send spurious interrupts after a
 	 * 'finger up' event, which will always cause a timeout.
 	 */
-	return 0;
+	return -ENOMSG;
 }
 
 static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)