From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753830AbdKMM6r (ORCPT ); Mon, 13 Nov 2017 07:58:47 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:49516 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753800AbdKMM6q (ORCPT ); Mon, 13 Nov 2017 07:58:46 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gerhard Bertelsmann , Marc Kleine-Budde Subject: [PATCH 4.4 53/56] can: sun4i: handle overrun in RX FIFO Date: Mon, 13 Nov 2017 13:56:17 +0100 Message-Id: <20171113125604.481747123@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171113125557.613444087@linuxfoundation.org> References: <20171113125557.613444087@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gerhard Bertelsmann 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- 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);