From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762045AbbA1FIL (ORCPT ); Wed, 28 Jan 2015 00:08:11 -0500 Received: from mail.kernel.org ([198.145.29.136]:38614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761441AbbA1ESr (ORCPT ); Tue, 27 Jan 2015 23:18:47 -0500 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, David Jander , Marc Kleine-Budde , Zefan Li Subject: [PATCH 3.4 56/91] can: flexcan: implement workaround for errata ERR005829 Date: Wed, 28 Jan 2015 12:07:58 +0800 Message-Id: <1422418236-12852-111-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Jander 3.4.105-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 25e924450fcb23c11c07c95ea8964dd9f174652e upstream. This patch implements the workaround mentioned in ERR005829: ERR005829: FlexCAN: FlexCAN does not transmit a message that is enabled to be transmitted in a specific moment during the arbitration process. Workaround: The workaround consists of two extra steps after setting up a message for transmission: Step 8: Reserve the first valid mailbox as an inactive mailbox (CODE=0b1000). If RX FIFO is disabled, this mailbox must be message buffer 0. Otherwise, the first valid mailbox can be found using the "RX FIFO filters" table in the FlexCAN chapter of the chip reference manual. Step 9: Write twice INACTIVE code (0b1000) into the first valid mailbox. Signed-off-by: David Jander Signed-off-by: Marc Kleine-Budde Signed-off-by: Zefan Li --- drivers/net/can/flexcan.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 1331558..681fb9c 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -123,7 +123,9 @@ FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT) /* FLEXCAN interrupt flag register (IFLAG) bits */ -#define FLEXCAN_TX_BUF_ID 8 +/* Errata ERR005829 step7: Reserve first valid MB */ +#define FLEXCAN_TX_BUF_RESERVED 8 +#define FLEXCAN_TX_BUF_ID 9 #define FLEXCAN_IFLAG_BUF(x) BIT(x) #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7) #define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6) @@ -317,6 +319,14 @@ static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id); flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); + /* Errata ERR005829 step8: + * Write twice INACTIVE(0x8) code to first MB. + */ + flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, + ®s->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl); + flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, + ®s->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl); + return NETDEV_TX_OK; } @@ -752,6 +762,10 @@ static int flexcan_chip_start(struct net_device *dev) ®s->cantxfg[i].can_ctrl); } + /* Errata ERR005829: mark first TX mailbox as INACTIVE */ + flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, + ®s->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl); + /* mark TX mailbox as INACTIVE */ flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); -- 1.9.1