Re: [PATCH net-next 08/14] net/mlx4: Remove obsolete 32-bit DMA mask fallback

[Tariq Toukan <tariqt@nvidia.com>]

On 03/09/2026 11:43, Ruizhe Zhou wrote:
> The DMA API guarantees support for masks of 32 bits or wider and
> explicitly identifies retrying a 32-bit mask after a 64-bit request as
> incorrect:
> https://docs.kernel.org/core-api/dma-api-howto.html#dma-addressing-capabilities
> 
> Remove the obsolete fallback while retaining the error check so that a
> genuine DMA setup failure is still reported and aborts initialization.
> 

You also switched dev_warn into dev_err.
Patch LGTM.

Reviewed-by: Tariq Toukan <tariqt@nvidia.com>

> Signed-off-by: Ruizhe Zhou <zhouruizhe@resnics.com>
> ---
>   drivers/net/ethernet/mellanox/mlx4/main.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> index c851daa5da9f..036135df23bf 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> @@ -3863,12 +3863,8 @@ static int __mlx4_init_one(struct pci_dev *pdev, int pci_dev_data,
>   
>   	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>   	if (err) {
> -		dev_warn(&pdev->dev, "Warning: couldn't set 64-bit PCI DMA mask\n");
> -		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> -		if (err) {
> -			dev_err(&pdev->dev, "Can't set PCI DMA mask, aborting\n");
> -			goto err_release_regions;
> -		}
> +		dev_err(&pdev->dev, "Can't set PCI DMA mask, aborting\n");
> +		goto err_release_regions;


>   	}
>   
>   	/* Allow large DMA segments, up to the firmware limit of 1 GB */