Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753984AbaKAW4o (ORCPT ); Sat, 1 Nov 2014 18:56:44 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60106 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbaKAWj1 (ORCPT ); Sat, 1 Nov 2014 18:39:27 -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" Date: Sat, 01 Nov 2014 22:28:03 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 064/102] can: flexcan: put TX mailbox into TX_INACTIVE mode after tx-complete 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: 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 [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/net/can/flexcan.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -632,6 +632,9 @@ static irqreturn_t flexcan_irq(int irq, if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) { /* tx_bytes is incremented in flexcan_start_xmit */ stats->tx_packets++; + /* 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); } -- 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/