6.6-stable review patch. If anyone has any objections, please let me know.
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From: Horatiu Vultur horatiu.vultur@microchip.com
[ Upstream commit 603ead96582d85903baec2d55f021b8dac5c25d2 ]
Both registers used when doing manual injection or fdma injection are shared between all the net devices of the switch. It was noticed that when having two process which each of them trying to inject frames on different ethernet ports, that the HW started to behave strange, by sending out more frames then expected. When doing fdma injection it is required to set the frame in the DCB and then make sure that the next pointer of the last DCB is invalid. But because there is no locks for this, then easily this pointer between the DCB can be broken and then it would create a loop of DCBs. And that means that the HW will continuously transmit these frames in a loop. Until the SW will break this loop. Therefore to fix this issue, add a spin lock for when accessing the registers for manual or fdma injection.
Signed-off-by: Horatiu Vultur horatiu.vultur@microchip.com Reviewed-by: Daniel Machon daniel.machon@microchip.com Fixes: f3cad2611a77 ("net: sparx5: add hostmode with phylink support") Link: https://lore.kernel.org/r/20240219080043.1561014-1-horatiu.vultur@microchip.... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/microchip/sparx5/sparx5_main.c | 1 + drivers/net/ethernet/microchip/sparx5/sparx5_main.h | 1 + drivers/net/ethernet/microchip/sparx5/sparx5_packet.c | 2 ++ 3 files changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c index dc9af480bfea1..8f116982c08a2 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c @@ -757,6 +757,7 @@ static int mchp_sparx5_probe(struct platform_device *pdev) platform_set_drvdata(pdev, sparx5); sparx5->pdev = pdev; sparx5->dev = &pdev->dev; + spin_lock_init(&sparx5->tx_lock);
/* Do switch core reset if available */ reset = devm_reset_control_get_optional_shared(&pdev->dev, "switch"); diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h index 6f565c0c0c3dc..316fed5f27355 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h @@ -280,6 +280,7 @@ struct sparx5 { int xtr_irq; /* Frame DMA */ int fdma_irq; + spinlock_t tx_lock; /* lock for frame transmission */ struct sparx5_rx rx; struct sparx5_tx tx; /* PTP */ diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c index 6db6ac6a3bbc2..ac7e1cffbcecf 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c @@ -244,10 +244,12 @@ netdev_tx_t sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev) }
skb_tx_timestamp(skb); + spin_lock(&sparx5->tx_lock); if (sparx5->fdma_irq > 0) ret = sparx5_fdma_xmit(sparx5, ifh, skb); else ret = sparx5_inject(sparx5, ifh, skb, dev); + spin_unlock(&sparx5->tx_lock);
if (ret == -EBUSY) goto busy;