From mboxrd@z Thu Jan 1 00:00:00 1970 From: GBert Subject: [PATCH v2] can: sun4i: fix overrun Date: Fri, 27 Oct 2017 14:46:51 +0200 Message-ID: <1509108411-9614-1-git-send-email-info@gerhard-bertelsmann.de> References: <5511583c-37ac-c6b7-f88d-1fd740fae3f5 () pengutronix ! de> Return-path: Received: from mail.rdts.de ([195.243.153.28]:36804 "EHLO mail.rdts.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752549AbdJ0MrE (ORCPT ); Fri, 27 Oct 2017 08:47:04 -0400 In-Reply-To: <5511583c-37ac-c6b7-f88d-1fd740fae3f5 () pengutronix ! de> Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org Cc: Gerhard Bertelsmann From: Gerhard Bertelsmann 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. V2: no duplicate error reporting --- drivers/net/can/sun4i_can.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c index 68ef0a4..bcec511 100644 --- a/drivers/net/can/sun4i_can.c +++ b/drivers/net/can/sun4i_can.c @@ -539,6 +539,11 @@ 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 */ + err = set_reset_mode(dev); + err = set_normal_mode(dev); + /* clear bit */ sun4i_can_write_cmdreg(priv, SUN4I_CMD_CLEAR_OR_FLAG); } @@ -653,8 +658,9 @@ 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); -- 1.7.9.5