| From | 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 |
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3.13.11.9 -stable review patch. If anyone has any objections, please let me know.
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From: Marc Kleine-Budde <mkl@pengutronix.de>
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 <mkl@pengutronix.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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
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