[net,v3] net: sparx5: Add spinlock for frame transmission from CPU
Commit Message
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")
---
v2->v3:
- add missing fix tag as it is targeting net
v1->v2:
- target net instead of net-next
---
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(+)
Comments
Hello:
This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:
On Mon, 19 Feb 2024 09:00:43 +0100 you wrote:
> 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.
>
> [...]
Here is the summary with links:
- [net,v3] net: sparx5: Add spinlock for frame transmission from CPU
https://git.kernel.org/netdev/net/c/603ead96582d
You are awesome, thank you!
@@ -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");
@@ -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 */
@@ -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;