[PATCH net] net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_xmit()

[PATCH net] net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_xmit()

[Lorenzo Bianconi]

In order to respect the original descriptor order and avoid any
potential IOMMU fault or memory corruption, move pending queue entries
to the head of hw queue tx_list if the DMA mapping of current inflight
packet fails in airoha_dev_xmit routine.

Fixes: 3f47e67dff1f7 ("net: airoha: Add the capability to consume out-of-order DMA tx descriptors")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 5effb4a4ae84..82018a085e46 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -2123,14 +2123,14 @@ static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 error_unmap:
-	while (!list_empty(&tx_list)) {
+	list_for_each_entry(e, &tx_list, list) {
 		e = list_first_entry(&tx_list, struct airoha_queue_entry,
 				     list);
 		dma_unmap_single(dev->dev.parent, e->dma_addr, e->dma_len,
 				 DMA_TO_DEVICE);
 		e->dma_addr = 0;
-		list_move_tail(&e->list, &q->tx_list);
 	}
+	list_splice(&tx_list, &q->tx_list);
 
 	spin_unlock_bh(&q->lock);
 error:

---
base-commit: 3bc179bc7146c26c9dff75d2943d10528274e301
change-id: 20260428-airoha-xmit-unmap-error-path-8125594efb23

Best regards,
-- 
Lorenzo Bianconi <lorenzo@kernel.org>

Re: [PATCH net] net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_xmit()

[Paolo Abeni]

On 4/28/26 10:44 AM, Lorenzo Bianconi wrote:
> In order to respect the original descriptor order and avoid any
> potential IOMMU fault or memory corruption, move pending queue entries
> to the head of hw queue tx_list if the DMA mapping of current inflight
> packet fails in airoha_dev_xmit routine.
> 
> Fixes: 3f47e67dff1f7 ("net: airoha: Add the capability to consume out-of-order DMA tx descriptors")
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  drivers/net/ethernet/airoha/airoha_eth.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> index 5effb4a4ae84..82018a085e46 100644
> --- a/drivers/net/ethernet/airoha/airoha_eth.c
> +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> @@ -2123,14 +2123,14 @@ static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb,
>  	return NETDEV_TX_OK;
>  
>  error_unmap:
> -	while (!list_empty(&tx_list)) {
> +	list_for_each_entry(e, &tx_list, list) {
>  		e = list_first_entry(&tx_list, struct airoha_queue_entry,
>  				     list);

Coccinelle says:

+/srv/nipa-builds-contest/testing/wt-cocci/drivers/net/ethernet/airoha/airoha_eth.c:2123:1-20:
iterator with update on line 2124

I guess you should additionally drop the statement above.

/P

Re: [PATCH net] net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_xmit()

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 1475 bytes --]

> On 4/28/26 10:44 AM, Lorenzo Bianconi wrote:
> > In order to respect the original descriptor order and avoid any
> > potential IOMMU fault or memory corruption, move pending queue entries
> > to the head of hw queue tx_list if the DMA mapping of current inflight
> > packet fails in airoha_dev_xmit routine.
> > 
> > Fixes: 3f47e67dff1f7 ("net: airoha: Add the capability to consume out-of-order DMA tx descriptors")
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> >  drivers/net/ethernet/airoha/airoha_eth.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> > index 5effb4a4ae84..82018a085e46 100644
> > --- a/drivers/net/ethernet/airoha/airoha_eth.c
> > +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> > @@ -2123,14 +2123,14 @@ static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb,
> >  	return NETDEV_TX_OK;
> >  
> >  error_unmap:
> > -	while (!list_empty(&tx_list)) {
> > +	list_for_each_entry(e, &tx_list, list) {
> >  		e = list_first_entry(&tx_list, struct airoha_queue_entry,
> >  				     list);
> 
> Coccinelle says:
> 
> +/srv/nipa-builds-contest/testing/wt-cocci/drivers/net/ethernet/airoha/airoha_eth.c:2123:1-20:
> iterator with update on line 2124
> 
> I guess you should additionally drop the statement above.

ack, sorry. I will fix it in v2.

Regards,
Lorenzo

> 
> /P
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]