Re: [PATCH net v2] net: stmmac: thead: Enable TX clock before MAC initialization

[Simon Horman <horms@kernel.org>]

On Fri, Aug 08, 2025 at 10:34:48AM +0000, Yao Zi wrote:

...

> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> index f2946bea0bc2..50c1920bde6a 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> @@ -152,7 +152,7 @@ static int thead_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
>  static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
>  {
>  	struct thead_dwmac *dwmac = plat->bsp_priv;
> -	u32 reg;
> +	u32 reg, div;
>  
>  	switch (plat->mac_interface) {
>  	case PHY_INTERFACE_MODE_MII:
> @@ -164,6 +164,13 @@ static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
>  	case PHY_INTERFACE_MODE_RGMII_RXID:
>  	case PHY_INTERFACE_MODE_RGMII_TXID:
>  		/* use pll */
> +		div = clk_get_rate(plat->stmmac_clk) / rgmii_clock(SPEED_1000);
> +		reg = FIELD_PREP(GMAC_PLLCLK_DIV_EN, 1) |
> +		      FIELD_PREP(GMAC_PLLCLK_DIV_NUM, div),

Sorry for not noticing this before sending my previous email.

Although the code above is correct. I think it would be clearer
to use ';' rather than ',' at the end of the line above. Perhaps ','
is a typo.(',' is next to ';' on my keyboard at least).

Flagged by Clang 20.1.8 with -Wcomma

> +
> +		writel(0, dwmac->apb_base + GMAC_PLLCLK_DIV);
> +		writel(reg, dwmac->apb_base + GMAC_PLLCLK_DIV);
> +
>  		writel(GMAC_GTXCLK_SEL_PLL, dwmac->apb_base + GMAC_GTXCLK_SEL);
>  		reg = GMAC_TX_CLK_EN | GMAC_TX_CLK_N_EN | GMAC_TX_CLK_OUT_EN |
>  		      GMAC_RX_CLK_EN | GMAC_RX_CLK_N_EN;

-- 
pw-bot: changes-requested.