Re: [PATCH net-next 01/10] net: stmmac: dwxgmac: Enable EDMA by default

[David Miller]

From: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>
Date: Wed, 26 Jun 2019 15:47:35 +0200

> @@ -122,6 +122,8 @@ static void dwxgmac2_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
>  	}
>  
>  	writel(value, ioaddr + XGMAC_DMA_SYSBUS_MODE);
> +	writel(GENMASK(29, 0), ioaddr + XGMAC_TX_EDMA_CTRL);
> +	writel(GENMASK(29, 0), ioaddr + XGMAC_RX_EDMA_CTRL);
>  }

This mask is magic and there is no indication what the bits mean and
in particular what it means to set bits 0 -- 29

You have to document what these bits mean and thus what these register
writes actually do.