From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH 4/8] can: flexcan: correctly initialize mailboxes Date: Thu, 18 Sep 2014 12:40:58 +0200 Message-ID: <1411036862-13255-5-git-send-email-mkl@pengutronix.de> References: <1411036862-13255-1-git-send-email-mkl@pengutronix.de> Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, David Jander , linux-stable , Marc Kleine-Budde To: netdev@vger.kernel.org Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:37895 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756574AbaIRKlN (ORCPT ); Thu, 18 Sep 2014 06:41:13 -0400 In-Reply-To: <1411036862-13255-1-git-send-email-mkl@pengutronix.de> Sender: netdev-owner@vger.kernel.org List-ID: From: David Jander Apparently mailboxes may contain random data at startup, causing some of them being prepared for message reception. This causes overruns being missed or even confusing the IRQ check for trasmitted messages, increasing the transmit counter instead of the error counter. This patch initializes all mailboxes after the FIFO as RX_INACTIVE. Signed-off-by: David Jander Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 76dcbca..fc076952 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -812,6 +812,7 @@ static int flexcan_chip_start(struct net_device *dev) struct flexcan_regs __iomem *regs = priv->base; int err; u32 reg_mcr, reg_ctrl; + int i; /* enable module */ err = flexcan_chip_enable(priv); @@ -878,6 +879,12 @@ static int flexcan_chip_start(struct net_device *dev) netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl); flexcan_write(reg_ctrl, ®s->ctrl); + /* clear and invalidate all mailboxes first */ + for (i = FLEXCAN_TX_BUF_ID; i < ARRAY_SIZE(regs->cantxfg); i++) { + flexcan_write(FLEXCAN_MB_CODE_RX_INACTIVE, + ®s->cantxfg[i].can_ctrl); + } + /* mark TX mailbox as INACTIVE */ flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); -- 2.1.0