> The driver calls dma_set_coherent_mask() but never dma_set_mask(),
> leaving the streaming DMA mask at the bus default. On the non-coherent
> EN7581 platform (Cortex-A53), this causes the NPU mailbox to hang
> after approximately 41 calls when using streaming DMA mappings.
> 
> Replace dma_set_coherent_mask() with dma_set_mask_and_coherent() to
> set both the streaming and coherent DMA masks, matching standard
> driver practice.
> 
> Fixes: 6f884eb87a79 ("net: airoha: Fix DMA direction for NPU mailbox buffer")
> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260814110017.2795022-1-pawlik.dan@gmail.com/
> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260809152813.585797-1-pawlik.dan@gmail.com/
> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260805070851.2885888-1-pawlik.dan@gmail.com/
> Assisted-by: Claude:claude-opus-4-6
> Signed-off-by: Daniel Pawlik <pawlik.dan@gmail.com>

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>

> ---
>  drivers/net/ethernet/airoha/airoha_npu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ethernet/airoha/airoha_npu.c
> index b679bed952de..4045d1eb93ea 100644
> --- a/drivers/net/ethernet/airoha/airoha_npu.c
> +++ b/drivers/net/ethernet/airoha/airoha_npu.c
> @@ -766,7 +766,7 @@ static int airoha_npu_probe(struct platform_device *pdev)
>  		npu->irqs[i] = irq;
>  	}
>  
> -	err = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
> +	err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
>  	if (err)
>  		return err;
>  
> -- 
> 2.55.0
>