Subject: Re: [PATCH net-next v3 1/3] net: stmmac: Add basic dwxgmac4 support to stmmac core

From: "Russell King (Oracle)" <[email-masked]>
Date: Fri, 2 Aug 2024 09:21:39 +0100

On Thu, Aug 01, 2024 at 08:18:20PM -0700, [email-masked] wrote:
> +static int rd_dma_ch_ind(void __iomem *ioaddr, u8 mode, u32 channel)
> +{
> +	u32 reg_val = 0;
> +	u32 val = 0;

val is unnecessary.

> +
> +	reg_val |= mode << XGMAC4_MSEL_SHIFT & XGMAC4_MODE_SELECT;

Consider using:

	reg_val |= FIELD_PREP(XGMAC4_MODE_SELECT, mode);

and similarly everywhere else you use a shift and mask. With this, you
can remove _all_ _SHIFT definitions in your header file.

> +	reg_val |= channel << XGMAC4_AOFF_SHIFT & XGMAC4_ADDR_OFFSET;
> +	reg_val |= XGMAC4_CMD_TYPE | XGMAC4_OB;
> +	writel(reg_val, ioaddr + XGMAC4_DMA_CH_IND_CONTROL);
> +	val = readl(ioaddr + XGMAC4_DMA_CH_IND_DATA);
> +	return val;

	return readl(ioaddr + XGMAC4_DMA_CH_IND_DATA);

...

> +void dwxgmac4_dma_init(void __iomem *ioaddr,
> +		       struct stmmac_dma_cfg *dma_cfg, int atds)
> +{
> +	u32 value;
> +	u32 i;
> +
> +	value = readl(ioaddr + XGMAC_DMA_SYSBUS_MODE);
> +
> +	if (dma_cfg->aal)
> +		value |= XGMAC_AAL;
> +
> +	if (dma_cfg->eame)
> +		value |= XGMAC_EAME;

What if dma_cfg doesn't have these bits set? Is it possible they will be
set in the register?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!