Patch "can: sun4i: handle overrun in RX FIFO" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    can: sun4i: handle overrun in RX FIFO

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     can-sun4i-handle-overrun-in-rx-fifo.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4dcf924c2eda0c47a5c53b7703e3dc65ddaa8920 Mon Sep 17 00:00:00 2001
From: Gerhard Bertelsmann <info@gerhard-bertelsmann.de>
Date: Mon, 6 Nov 2017 18:16:56 +0100
Subject: can: sun4i: handle overrun in RX FIFO

From: Gerhard Bertelsmann <info@gerhard-bertelsmann.de>

commit 4dcf924c2eda0c47a5c53b7703e3dc65ddaa8920 upstream.

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>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/can/sun4i_can.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- 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_devi
 		}
 		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(i
 			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);


Patches currently in stable-queue which might be from info@gerhard-bertelsmann.de are

queue-4.9/can-sun4i-handle-overrun-in-rx-fifo.patch