Re: [PATCH v2 1/2] phy: rockchip: naneng-combphy: Fix PCIe L1ss support RK3528

[Neil Armstrong <neil.armstrong@linaro.org>]

On 11/18/25 10:52, Shawn Lin wrote:
> When PCIe link enters L1 PM substates, the PHY will turn off its
> PLL for power-saving. However, it turns off the PLL too fast which
> leads the PHY to be broken. According to the PHY document, we need
> to delay PLL turnoff time.
> 
> Fixes: bbcca4fac873 ("phy: rockchip: naneng-combphy: Add RK3528 support")
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> ---
> 
> Changes in v2:
> - add more commit message
> 
>   drivers/phy/rockchip/phy-rockchip-naneng-combphy.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
> index a3ef198..e303bec 100644
> --- a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
> +++ b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
> @@ -21,6 +21,9 @@
>   #define REF_CLOCK_100MHz		(100 * HZ_PER_MHZ)
>   
>   /* RK3528 COMBO PHY REG */
> +#define RK3528_PHYREG5				0x14
> +#define RK3528_PHYREG5_GATE_TX_PCK_SEL		BIT(3)
> +#define RK3528_PHYREG5_GATE_TX_PCK_DLY_PLL_OFF	BIT(3)
>   #define RK3528_PHYREG6				0x18
>   #define RK3528_PHYREG6_PLL_KVCO			GENMASK(12, 10)
>   #define RK3528_PHYREG6_PLL_KVCO_VALUE		0x2
> @@ -504,6 +507,10 @@ static int rk3528_combphy_cfg(struct rockchip_combphy_priv *priv)
>   	case REF_CLOCK_100MHz:
>   		rockchip_combphy_param_write(priv->phy_grf, &cfg->pipe_clk_100m, true);
>   		if (priv->type == PHY_TYPE_PCIE) {
> +			/* Gate_tx_pck_sel length select for L1ss support */
> +			rockchip_combphy_updatel(priv, RK3528_PHYREG5_GATE_TX_PCK_SEL,
> +						 RK3528_PHYREG5_GATE_TX_PCK_DLY_PLL_OFF, RK3528_PHYREG5);
> +
>   			/* PLL KVCO tuning fine */
>   			val = FIELD_PREP(RK3528_PHYREG6_PLL_KVCO, RK3528_PHYREG6_PLL_KVCO_VALUE);
>   			rockchip_combphy_updatel(priv, RK3528_PHYREG6_PLL_KVCO, val,

Thanks for updating, it's clearer now !

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

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