Commit 603ead96 authored by Horatiu Vultur's avatar Horatiu Vultur Committed by Jakub Kicinski
Browse files

net: sparx5: Add spinlock for frame transmission from CPU 



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: default avatarHoratiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: default avatarDaniel Machon <daniel.machon@microchip.com>
Fixes: f3cad261 ("net: sparx5: add hostmode with phylink support")
Link: https://lore.kernel.org/r/20240219080043.1561014-1-horatiu.vultur@microchip.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1fde0ca3

drivers/net/ethernet/microchip/sparx5/sparx5_main.c

+1 −0
Original line number Diff line number Diff line
@@ -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");

drivers/net/ethernet/microchip/sparx5/sparx5_main.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/net/ethernet/microchip/sparx5/sparx5_packet.c

+2 −0
Original line number Diff line number Diff line
@@ -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;