From 1021dcf19db1387bc0db26d14bbcba719923a466 Mon Sep 17 00:00:00 2001 From: Anson Huang Date: Fri, 13 Dec 2019 14:02:30 -0800 Subject: [PATCH] Input: imx_sc_key - only take the valid data from SCU firmware as key state When reading key state from SCU, the response data from SCU firmware is 4 bytes due to MU message protocol, but ONLY the first byte is the key state, other 3 bytes could be some dirty data, so we should ONLY take the first byte as key state to avoid reporting incorrect state. Signed-off-by: Anson Huang Fixes: 688f1dfb69b4 ("Input: keyboard - imx_sc: Add i.MX system controller key support") Link: https://lore.kernel.org/r/1576202909-1661-1-git-send-email-Anson.Huang@nxp.com Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/imx_sc_key.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/input/keyboard/imx_sc_key.c b/drivers/input/keyboard/imx_sc_key.c index 53799527dc75..9f809aeb785c 100644 --- a/drivers/input/keyboard/imx_sc_key.c +++ b/drivers/input/keyboard/imx_sc_key.c @@ -78,7 +78,13 @@ static void imx_sc_check_for_events(struct work_struct *work) return; } - state = (bool)msg.state; + /* + * The response data from SCU firmware is 4 bytes, + * but ONLY the first byte is the key state, other + * 3 bytes could be some dirty data, so we should + * ONLY take the first byte as key state. + */ + state = (bool)(msg.state & 0xff); if (state ^ priv->keystate) { priv->keystate = state;