Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753595AbaKAWxd (ORCPT ); Sat, 1 Nov 2014 18:53:33 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60132 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751584AbaKAWj2 (ORCPT ); Sat, 1 Nov 2014 18:39:28 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Marc Kleine-Budde" , "David Jander" Date: Sat, 01 Nov 2014 22:28:03 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 062/102] can: flexcan: correctly initialize mailboxes In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.64-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: David Jander commit fc05b884a31dbf259cc73cc856e634ec3acbebb6 upstream. 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Ben Hutchings --- drivers/net/can/flexcan.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -679,6 +679,7 @@ static int flexcan_chip_start(struct net struct flexcan_regs __iomem *regs = priv->base; int err; u32 reg_mcr, reg_ctrl; + int i; /* enable module */ flexcan_chip_enable(priv); @@ -744,6 +745,12 @@ static int flexcan_chip_start(struct net dev_dbg(dev->dev.parent, "%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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/