can: peak/pcie_fd: fix echo_skb is occupied! bug

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>
This commit is contained in:
Stephane Grosjean 2018-03-08 09:30:28 +01:00 committed by Marc Kleine-Budde
parent 880dd464b4
commit e6048a00cf
2 changed files with 12 additions and 8 deletions

View file

@ -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;
}

View file

@ -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 */