This is a note to let you know that I've just added the patch titled
net: ftgmac100: Ensure tx descriptor updates are visible
to the 4.19-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:
net-ftgmac100-ensure-tx-descriptor-updates-are-visib.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b2ee7f437da10883fdb857fe2e4482977019c105
Author: Jacky Chou <jacky_chou@xxxxxxxxxxxxxx>
Date: Thu Aug 22 15:30:06 2024 +0800
net: ftgmac100: Ensure tx descriptor updates are visible
[ Upstream commit 4186c8d9e6af57bab0687b299df10ebd47534a0a ]
The driver must ensure TX descriptor updates are visible
before updating TX pointer and TX clear pointer.
This resolves TX hangs observed on AST2600 when running
iperf3.
Signed-off-by: Jacky Chou <jacky_chou@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 23c019d1278cd..f6ed8d167d53c 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -579,7 +579,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
(*processed)++;
return true;
- drop:
+drop:
/* Clean rxdes0 (which resets own bit) */
rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
@@ -663,6 +663,11 @@ static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
+ /* Ensure the descriptor config is visible before setting the tx
+ * pointer.
+ */
+ smp_wmb();
+
priv->tx_clean_pointer = ftgmac100_next_tx_pointer(priv, pointer);
return true;
@@ -816,6 +821,11 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb,
dma_wmb();
first->txdes0 = cpu_to_le32(f_ctl_stat);
+ /* Ensure the descriptor config is visible before setting the tx
+ * pointer.
+ */
+ smp_wmb();
+
/* Update next TX pointer */
priv->tx_pointer = pointer;
@@ -836,7 +846,7 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb,
return NETDEV_TX_OK;
- dma_err:
+dma_err:
if (net_ratelimit())
netdev_err(netdev, "map tx fragment failed\n");
@@ -858,7 +868,7 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb,
* last fragment, so we know ftgmac100_free_tx_packet()
* hasn't freed the skb yet.
*/
- drop:
+drop:
/* Drop the packet */
dev_kfree_skb_any(skb);
netdev->stats.tx_dropped++;
@@ -1444,7 +1454,7 @@ static void ftgmac100_reset_task(struct work_struct *work)
ftgmac100_init_all(priv, true);
netdev_dbg(netdev, "Reset done !\n");
- bail:
+bail:
if (priv->mii_bus)
mutex_unlock(&priv->mii_bus->mdio_lock);
if (netdev->phydev)
@@ -1515,15 +1525,15 @@ static int ftgmac100_open(struct net_device *netdev)
return 0;
- err_ncsi:
+err_ncsi:
napi_disable(&priv->napi);
netif_stop_queue(netdev);
- err_alloc:
+err_alloc:
ftgmac100_free_buffers(priv);
free_irq(netdev->irq, netdev);
- err_irq:
+err_irq:
netif_napi_del(&priv->napi);
- err_hw:
+err_hw:
iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
ftgmac100_free_rings(priv);
return err;
