From 59f415c2f5e20a6859e49626e8af4de983ff111c Mon Sep 17 00:00:00 2001 From: Jeroen Hofstee Date: Tue, 24 Sep 2019 18:45:52 +0000 Subject: [PATCH] can: ti_hecc: ti_hecc_stop(): stop the CPK on down When the interface goes down, the CPK should no longer take an active part in the CAN-bus communication, like sending acks and error frames. So enable configuration mode in ti_hecc_stop, so the CPK is no longer active. When a transceiver switch is present the acks and errors don't make it to the bus, but disabling the CPK then does prevent oddities, like ti_hecc_reset() failing, since the CPK can become bus-off and starts counting the 11 bit recessive bits, which seems to block the reset. It can also cause invalid interrupts and disrupt the CAN-bus, since transmission can be stopped in the middle of a message, by disabling the tranceiver while the CPK is sending. Since the CPK is disabled after normal power on, it is typically only seen when the interface is restarted. Signed-off-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/ti_hecc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c index 91188e6d4f78..eb8151154083 100644 --- a/drivers/net/can/ti_hecc.c +++ b/drivers/net/can/ti_hecc.c @@ -400,6 +400,9 @@ static void ti_hecc_stop(struct net_device *ndev) { struct ti_hecc_priv *priv = netdev_priv(ndev); + /* Disable the CPK; stop sending, erroring and acking */ + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + /* Disable interrupts and disable mailboxes */ hecc_write(priv, HECC_CANGIM, 0); hecc_write(priv, HECC_CANMIM, 0); -- 2.45.2