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Patch "can: peak/pcie_fd: fix echo_skb is occupied! bug" has been added to the 4.15-stable tree

PATCH [email protected] 1 participant 1 message Mar 25, 2018

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This is a note to let you know that I've just added the patch titled

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

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
can-peak-pcie_fd-fix-echo_skb-is-occupied-bug.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From e6048a00cfd0863d32f53b226e0b9a3633fc3332 Mon Sep 17 00:00:00 2001

From: Stephane Grosjean <[email protected]>
Date: Thu, 8 Mar 2018 09:30:28 +0100
Subject: can: peak/pcie_fd: fix echo_skb is occupied! bug

From: Stephane Grosjean <[email protected]>

commit e6048a00cfd0863d32f53b226e0b9a3633fc3332 upstream.

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 <[email protected]>
Signed-off-by Stephane Grosjean <[email protected]>
Cc linux-stable <[email protected]>
Signed-off-by Marc Kleine-Budde <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 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(-)
drivers/net/can/peak_canfd/peak_canfd.c +6 -6
@@ -262,7 +262,6 @@ static int pucan_handle_can_rx(struct pe
 
 		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 pe
 		/* 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
 	 */
 	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
 	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;
 }
drivers/net/can/peak_canfd/peak_pciefd_main.c +6 -2
@@ -349,8 +349,12 @@ static irqreturn_t pciefd_irq_handler(in
 		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 */

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/can-peak-pcie_fd-fix-echo_skb-is-occupied-bug.patch queue-4.15/can-peak-pcie_fd-remove-useless-code-when-interface-starts.patch