[PATCH 1/2] can: flexcan: Unlock mailbox also in timestamp based offloading

[Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>]

If the last mailbox is not unlocked explicitly there is a small window
where an already received but not yet stored frame is overwritten in
the SMB (Serial Message Buffer) by the next CAN frame.
Although it is said to be optional, explicitly unlock the mailbox.

Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/net/can/flexcan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 8e972ef08637..c9d30480aae9 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -720,8 +720,9 @@ static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
 			priv->write(BIT(n - 32), &regs->iflag2);
 	} else {
 		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
-		priv->read(&regs->timer);
 	}
+	/* Unlock mailbox */
+	priv->read(&regs->timer);
 
 	return 1;
 }
-- 
2.18.1