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 <Anson.Huang@nxp.com>
Fixes: 688f1dfb69 ("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 <dmitry.torokhov@gmail.com>
This commit is contained in:
Anson Huang 2019-12-13 14:02:30 -08:00 committed by Dmitry Torokhov
parent cb222aed03
commit 1021dcf19d
1 changed files with 7 additions and 1 deletions

View File

@ -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;