From patchwork Tue Oct 29 18:03:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 287008 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 273462C0345 for ; Wed, 30 Oct 2013 05:12:04 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1VbDln-00029H-MB; Tue, 29 Oct 2013 18:11:59 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1VbDjq-00014D-M8 for kernel-team@lists.ubuntu.com; Tue, 29 Oct 2013 18:09:58 +0000 Received: from c-67-160-231-162.hsd1.ca.comcast.net ([67.160.231.162] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1VbDfD-0001Bv-O9; Tue, 29 Oct 2013 18:05:12 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1VbDfB-00032Q-LA; Tue, 29 Oct 2013 11:05:09 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.8 27/81] can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX Date: Tue, 29 Oct 2013 11:03:48 -0700 Message-Id: <1383069882-11437-28-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1383069882-11437-1-git-send-email-kamal@canonical.com> References: <1383069882-11437-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 X-Extended-Stable: 3.8 Cc: Kamal Mostafa , Marc Kleine-Budde , =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.8.13.12 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Kleine-Budde commit d5a7b406c529e4595ce03dc8f6dcf7fa36f106fa upstream. In patch 0d1862e can: flexcan: fix flexcan_chip_start() on imx6 the loop in flexcan_chip_start() that iterates over all mailboxes after the soft reset of the CAN core was removed. This loop put all mailboxes (even the ones marked as reserved 1...7) into EMPTY/INACTIVE mode. On mailboxes 8...63, this aborts any pending TX messages. After a cold boot there is random garbage in the mailboxes, which leads to spontaneous transmit of CAN frames during first activation. Further if the interface was disabled with a pending message (usually due to an error condition on the CAN bus), this message is retransmitted after enabling the interface again. This patch fixes the regression by: 1) Limiting the maximum number of used mailboxes to 8, 0...7 are used by the RX FIFO, 8 is used by TX. 2) Marking the TX mailbox as EMPTY/INACTIVE, so that any pending TX of that mailbox is aborted. Cc: Lothar Waßmann Signed-off-by: Marc Kleine-Budde Signed-off-by: Kamal Mostafa --- drivers/net/can/flexcan.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 15d5abb..5817a39 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -62,7 +62,7 @@ #define FLEXCAN_MCR_BCC BIT(16) #define FLEXCAN_MCR_LPRIO_EN BIT(13) #define FLEXCAN_MCR_AEN BIT(12) -#define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf) +#define FLEXCAN_MCR_MAXMB(x) ((x) & 0x1f) #define FLEXCAN_MCR_IDAM_A (0 << 8) #define FLEXCAN_MCR_IDAM_B (1 << 8) #define FLEXCAN_MCR_IDAM_C (2 << 8) @@ -740,9 +740,11 @@ static int flexcan_chip_start(struct net_device *dev) * */ reg_mcr = flexcan_read(®s->mcr); + reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff); reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | - FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS; + FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS | + FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID); netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr); flexcan_write(reg_mcr, ®s->mcr); @@ -776,6 +778,10 @@ 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); + /* Abort any pending TX, mark Mailbox as INACTIVE */ + flexcan_write(FLEXCAN_MB_CNT_CODE(0x4), + ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); + /* acceptance mask/acceptance code (accept everything) */ flexcan_write(0x0, ®s->rxgmask); flexcan_write(0x0, ®s->rx14mask);