Re: [PATCH net-next V2 07/13] net/mlx5e: SHAMPO, Use page_pool DMA sync helper for SKB frags

[Dragos Tatulea]

On 12.11.26 10:40, netdev-bot+sashiko@xxxxxxxxxx wrote:
> Thank you for your contribution! Sashiko AI review found more severe
> issue(s) in other patches of this series. This mail is only an FYI, in case
> you want to address the nit picks below when you respin.
> 
> Low priority / nit picks for your consideration:
> 
> - [Low] The commit message describes this patch as preparation for data
>   direct only.
> 
> --
> 
> net/mlx5e: SHAMPO, Use page_pool DMA sync helper for SKB frags
> 
> This patch changes mlx5e_add_skb_frag() to call
> page_pool_dma_sync_netmem_for_cpu() instead of calling
> dma_sync_single_for_cpu() on rq->pdev directly. The stated reason is the
> upcoming data direct support, where SHAMPO payload netmem is mapped
> against the data direct device rather than rq->pdev.
> 
>> Switch to the page_pool DMA API which takes care of not calling
>> dma_sync_* for unreadable netmem. Do it only for the place where it
>> makes sense: SHAMPO payloads, the only RX buffers that can be
>> unreadable.
>>
>> Until now it was ok to call the dma_sync_* API directly. But with the
>> introduction of data direct it will no longer be correct: the payload
>> netmem of a data direct RQ is mapped against the data direct device,
>> not rq->pdev.
> 
> [Severity: Low]
> Is "Until now it was ok to call the dma_sync_* API directly" accurate?
> 
Indeed. Will amend commit message in v3.

Thanks,
Dragos