From de5944883ebbedbf5adc8497659772f5da7b7d72 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 16 Sep 2014 15:31:27 +0200 Subject: [PATCH] can: flexcan: put TX mailbox into TX_INACTIVE mode after tx-complete 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. Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- 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 54061c4bbf32..c17ae9eb7278 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -765,6 +765,9 @@ 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); } -- 2.20.1