From: Gerhard Bertelsmann <i...@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 <i...@gerhard-bertelsmann.de>
Cc: linux-stable <sta...@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <m...@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);
--
2.15.0
