Re: [bug report] net: airoha: Move DSA tag in DMA descriptor

[Lorenzo Bianconi <lorenzo@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 1395 bytes --]

On Mar 06, Dan Carpenter wrote:
> Hello Lorenzo Bianconi,
> 
> Commit af3cf757d5c9 ("net: airoha: Move DSA tag in DMA descriptor")
> from Feb 28, 2025 (linux-next), leads to the following Smatch static
> checker warning:
> 
> 	drivers/net/ethernet/airoha/airoha_eth.c:1722 airoha_get_dsa_tag()
> 	warn: 'dp' isn't an ERR_PTR
> 
> drivers/net/ethernet/airoha/airoha_eth.c
>     1710 static u32 airoha_get_dsa_tag(struct sk_buff *skb, struct net_device *dev)
>     1711 {
>     1712 #if IS_ENABLED(CONFIG_NET_DSA)
>     1713         struct ethhdr *ehdr;
>     1714         struct dsa_port *dp;
>     1715         u8 xmit_tpid;
>     1716         u16 tag;
>     1717 
>     1718         if (!netdev_uses_dsa(dev))
>     1719                 return 0;
>     1720 
>     1721         dp = dev->dsa_ptr;
> --> 1722         if (IS_ERR(dp))
> 
> Why would this be an error pointer?  Is this supposed to be a check for
> NULL?

yes, right. Moreover NULL pointer check is already done in netdev_uses_dsa() so
we can drop it. I will post a fix for it.

Regards,
Lorenzo

> 
>     1723                 return 0;
>     1724 
>     1725         if (dp->tag_ops->proto != DSA_TAG_PROTO_MTK)
>     1726                 return 0;
>     1727 
>     1728         if (skb_cow_head(skb, 0))
>     1729                 return 0;
>     1730 
> 
> regards,
> dan carpenter

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