The driver calls netif_napi_set_irq() and then calls netif_napi_add(), which calls netif_napi_add_weight(). At the end of netif_napi_add_weight() is a call to netif_napi_set_irq(napi, -1), which clears the previously set napi->irq value. Fix this by calling netif_napi_set_irq() after calling netif_napi_add().
This was found when reviewing another patch and I have no way to test this, but the fix seemed relatively straight forward.
Cc: stable@vger.kernel.org Fixes: bc6107771bb4 ("eth: fbnic: Allocate a netdevice and napi vectors with queues") Signed-off-by: Brett Creeley brett.creeley@amd.com --- drivers/net/ethernet/meta/fbnic/fbnic_txrx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c index 0ed4c9fff5d8..72f88ae7815f 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c @@ -1012,14 +1012,14 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn, nv->fbd = fbd; nv->v_idx = v_idx;
- /* Record IRQ to NAPI struct */ - netif_napi_set_irq(&nv->napi, - pci_irq_vector(to_pci_dev(fbd->dev), nv->v_idx)); - /* Tie napi to netdev */ list_add(&nv->napis, &fbn->napis); netif_napi_add(fbn->netdev, &nv->napi, fbnic_poll);
+ /* Record IRQ to NAPI struct */ + netif_napi_set_irq(&nv->napi, + pci_irq_vector(to_pci_dev(fbd->dev), nv->v_idx)); + /* Tie nv back to PCIe dev */ nv->dev = fbd->dev;
On Thu, Sep 12, 2024 at 10:49:22AM -0700, Brett Creeley wrote:
The driver calls netif_napi_set_irq() and then calls netif_napi_add(), which calls netif_napi_add_weight(). At the end of netif_napi_add_weight() is a call to netif_napi_set_irq(napi, -1), which clears the previously set napi->irq value. Fix this by calling netif_napi_set_irq() after calling netif_napi_add().
This was found when reviewing another patch and I have no way to test this, but the fix seemed relatively straight forward.
Cc: stable@vger.kernel.org Fixes: bc6107771bb4 ("eth: fbnic: Allocate a netdevice and napi vectors with queues") Signed-off-by: Brett Creeley brett.creeley@amd.com
I agree with your analysis, but I'm not sure if this needs to be backported to other kernels because: - It is not a device that is easily available (currently), - The bug is relatively minor
I'm not a maintainer so I'll let those folks decide if this should be a net-next thing to reduce load on the stable folks.
In any case:
Reviewed-by: Joe Damato jdamato@fastly.com
On 12/09/2024 18:49, Brett Creeley wrote:
The driver calls netif_napi_set_irq() and then calls netif_napi_add(), which calls netif_napi_add_weight(). At the end of netif_napi_add_weight() is a call to netif_napi_set_irq(napi, -1), which clears the previously set napi->irq value. Fix this by calling netif_napi_set_irq() after calling netif_napi_add().
This was found when reviewing another patch and I have no way to test this, but the fix seemed relatively straight forward. Cc: stable@vger.kernel.org Fixes: bc6107771bb4 ("eth: fbnic: Allocate a netdevice and napi vectors with queues") Signed-off-by: Brett Creeley brett.creeley@amd.com
I agree that irq vector is lost without this patch.
Reviewed-by: Vadim Fedorenko vadim.fedorenko@linux.dev
Hello:
This patch was applied to netdev/net.git (main) by Jakub Kicinski kuba@kernel.org:
On Thu, 12 Sep 2024 10:49:22 -0700 you wrote:
The driver calls netif_napi_set_irq() and then calls netif_napi_add(), which calls netif_napi_add_weight(). At the end of netif_napi_add_weight() is a call to netif_napi_set_irq(napi, -1), which clears the previously set napi->irq value. Fix this by calling netif_napi_set_irq() after calling netif_napi_add().
This was found when reviewing another patch and I have no way to test this, but the fix seemed relatively straight forward.
[...]
Here is the summary with links: - [net] fbnic: Set napi irq value after calling netif_napi_add https://git.kernel.org/netdev/net/c/9f3e7f11f21a
You are awesome, thank you!
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Brett Creeley -
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Vadim Fedorenko