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Commit 4dcf924c authored by Gerhard Bertelsmann's avatar Gerhard Bertelsmann Committed by Marc Kleine-Budde
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can: sun4i: handle overrun in RX FIFO 



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: default avatarGerhard Bertelsmann <info@gerhard-bertelsmann.de>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent fb5f0b3e

drivers/net/can/sun4i_can.c

+10 −2
Original line number Diff line number Diff line
@@ -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);