From: Gerhard Bertelsmann info@gerhard-bertelsmann.de

SUN4Is CAN IP has a 64 byte deep FIFO buffer. If the buffer is not drained fast enough (overrun) it's getting mangled. Already received frames are dropped - the data can't be restored.

Signed-off-by: Gerhard Bertelsmann info@gerhard-bertelsmann.de Cc: linux-stable stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/sun4i_can.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c index b0c80859f746..1ac2090a1721 100644 --- a/drivers/net/can/sun4i_can.c +++ b/drivers/net/can/sun4i_can.c @@ -539,6 +539,13 @@ static int sun4i_can_err(struct net_device *dev, u8 isrc, u8 status) } stats->rx_over_errors++; stats->rx_errors++; + + /* reset the CAN IP by entering reset mode + * ignoring timeout error + */ + set_reset_mode(dev); + set_normal_mode(dev); + /* clear bit */ sun4i_can_write_cmdreg(priv, SUN4I_CMD_CLEAR_OR_FLAG); } @@ -653,8 +660,9 @@ static irqreturn_t sun4i_can_interrupt(int irq, void *dev_id) netif_wake_queue(dev); can_led_event(dev, CAN_LED_EVENT_TX); } - if (isrc & SUN4I_INT_RBUF_VLD) { - /* receive interrupt */ + if ((isrc & SUN4I_INT_RBUF_VLD) && + !(isrc & SUN4I_INT_DATA_OR)) { + /* receive interrupt - don't read if overrun occurred */ while (status & SUN4I_STA_RBUF_RDY) { /* RX buffer is not empty */ sun4i_can_rx(dev);