can: flexcan: Unlock the MB unconditionally

Unlock the MB irrespective of reception method being FIFO or timestamp
based. It is optional but recommended to unlock Mailbox as soon as
possible and make it available for reception.

Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 8e972ef0863769e88a2c9d6cec37408d66566292..0431f8d05518ad7a99b47c627e1a508152c27c95 100644 (file)
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -720,9 +720,14 @@ 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);
        }
 
+       /* Read the Free Running Timer. It is optional but recommended
+        * to unlock Mailbox as soon as possible and make it available
+        * for reception.
+        */
+       priv->read(&regs->timer);
+
        return 1;
 }