| From | Ben Hutchings <> | Date | Sat, 01 Nov 2014 22:28:03 +0000 | Subject | [PATCH 3.2 064/102] can: flexcan: put TX mailbox into TX_INACTIVE mode after tx-complete |
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3.2.64-rc1 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> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- 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); }
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