From: Stephane Grosjean s.grosjean@peak-system.com

This patch makes atomic the handling of the linux-can echo_skb array and the network tx queue. This prevents from the "BUG! echo_skb is occupied!" message to be printed by the linux-can core, in SMP environments.

Reported-by: Diana Burgess diana@peloton-tech.com Signed-off-by: Stephane Grosjean s.grosjean@peak-system.com Cc: linux-stable stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/peak_canfd/peak_canfd.c | 12 ++++++------ drivers/net/can/peak_canfd/peak_pciefd_main.c | 8 ++++++-- 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c index 55513411a82e..6fa66231ed8e 100644 --- a/drivers/net/can/peak_canfd/peak_canfd.c +++ b/drivers/net/can/peak_canfd/peak_canfd.c @@ -262,7 +262,6 @@ static int pucan_handle_can_rx(struct peak_canfd_priv *priv,

spin_lock_irqsave(&priv->echo_lock, flags); can_get_echo_skb(priv->ndev, msg->client); - spin_unlock_irqrestore(&priv->echo_lock, flags);

/* count bytes of the echo instead of skb */ stats->tx_bytes += cf_len; @@ -271,6 +270,7 @@ static int pucan_handle_can_rx(struct peak_canfd_priv *priv, /* restart tx queue (a slot is free) */ netif_wake_queue(priv->ndev);

+ spin_unlock_irqrestore(&priv->echo_lock, flags); return 0; }

@@ -726,11 +726,6 @@ static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb, */ should_stop_tx_queue = !!(priv->can.echo_skb[priv->echo_idx]);

- spin_unlock_irqrestore(&priv->echo_lock, flags); - - /* write the skb on the interface */ - priv->write_tx_msg(priv, msg); - /* stop network tx queue if not enough room to save one more msg too */ if (priv->can.ctrlmode & CAN_CTRLMODE_FD) should_stop_tx_queue |= (room_left < @@ -742,6 +737,11 @@ static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb, if (should_stop_tx_queue) netif_stop_queue(ndev);

+ spin_unlock_irqrestore(&priv->echo_lock, flags); + + /* write the skb on the interface */ + priv->write_tx_msg(priv, msg); + return NETDEV_TX_OK; }

diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c b/drivers/net/can/peak_canfd/peak_pciefd_main.c index 788c3464a3b0..3c51a884db87 100644 --- a/drivers/net/can/peak_canfd/peak_pciefd_main.c +++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c @@ -349,8 +349,12 @@ static irqreturn_t pciefd_irq_handler(int irq, void *arg) priv->tx_pages_free++; spin_unlock_irqrestore(&priv->tx_lock, flags);

- /* wake producer up */ - netif_wake_queue(priv->ucan.ndev); + /* wake producer up (only if enough room in echo_skb array) */ + spin_lock_irqsave(&priv->ucan.echo_lock, flags); + if (!priv->ucan.can.echo_skb[priv->ucan.echo_idx]) + netif_wake_queue(priv->ucan.ndev); + + spin_unlock_irqrestore(&priv->ucan.echo_lock, flags); }

/* re-enable Rx DMA transfer for this CAN */