Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758592AbaJIVeT (ORCPT ); Thu, 9 Oct 2014 17:34:19 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59251 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757414AbaJIVIh (ORCPT ); Thu, 9 Oct 2014 17:08:37 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Marc Kleine-Budde , Kamal Mostafa Subject: [PATCH 3.13 123/163] can: flexcan: put TX mailbox into TX_INACTIVE mode after tx-complete Date: Thu, 9 Oct 2014 14:02:28 -0700 Message-Id: <1412888588-26755-124-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412888588-26755-1-git-send-email-kamal@canonical.com> References: <1412888588-26755-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Kleine-Budde commit de5944883ebbedbf5adc8497659772f5da7b7d72 upstream. After sending a RTR frame the TX mailbox becomes a RX_EMPTY mailbox. To avoid side effects when the RX-FIFO is full, this patch puts the TX mailbox into TX_INACTIVE mode in the transmission complete interrupt handler. This, of course, leaves a race window between the actual completion of the transmission and the handling of tx-complete interrupt. However this is the best we can do without busy polling the tx complete interrupt. Signed-off-by: Marc Kleine-Budde Signed-off-by: Kamal Mostafa --- drivers/net/can/flexcan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 3a1859b..deea3a9 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -702,6 +702,9 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) stats->tx_bytes += can_get_echo_skb(dev, 0); stats->tx_packets++; can_led_event(dev, CAN_LED_EVENT_TX); + /* after sending a RTR frame mailbox is in RX mode */ + flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE, + ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1); netif_wake_queue(dev); } -- 1.9.1 -- 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/