linux-kernel - Re: [PATCH net-next] r8169: set EEE speed down ratio to 1

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Message-ID: <d78dd279-54ed-46c3-b0b1-09c0be04557a@gmail.com>
Date: Thu, 4 Sep 2025 08:16:04 +0200
From: Heiner Kallweit <hkallweit1@...il.com>
To: ChunHao Lin <hau@...ltek.com>, nic_swsd@...ltek.com,
 andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com,
 kuba@...nel.org, pabeni@...hat.com
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next] r8169: set EEE speed down ratio to 1

On 9/4/2025 4:11 AM, ChunHao Lin wrote:
> EEE speed down ratio (mac ocp 0xe056[7:4]) is used to control EEE speed down
> rate. The larger this value is, the more power can save. But it actually save
> less power then expected, but will impact compatibility. So set it to 1 (mac
> ocp 0xe056[7:4] = 0) to improve compatibility.
> 
Hi Hau,

what kind of speed is this referring to? Some clock, or link speed, or ..?
Is EEE speed down a Realtek-specific feature?

Are there known issues with the values used currently? Depending on the
answer we might consider this a fix.

Heiner

> Signed-off-by: ChunHao Lin <hau@...ltek.com>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 9c601f271c02..e5427dfce268 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -3409,7 +3409,7 @@ static void rtl_hw_start_8168h_1(struct rtl8169_private *tp)
>  		r8168_mac_ocp_modify(tp, 0xd412, 0x0fff, sw_cnt_1ms_ini);
>  	}
>  
> -	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0070);
> +	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0000);
>  	r8168_mac_ocp_modify(tp, 0xe052, 0x6000, 0x8008);
>  	r8168_mac_ocp_modify(tp, 0xe0d6, 0x01ff, 0x017f);
>  	r8168_mac_ocp_modify(tp, 0xd420, 0x0fff, 0x047f);
> @@ -3514,7 +3514,7 @@ static void rtl_hw_start_8117(struct rtl8169_private *tp)
>  		r8168_mac_ocp_modify(tp, 0xd412, 0x0fff, sw_cnt_1ms_ini);
>  	}
>  
> -	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0070);
> +	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0000);
>  	r8168_mac_ocp_write(tp, 0xea80, 0x0003);
>  	r8168_mac_ocp_modify(tp, 0xe052, 0x0000, 0x0009);
>  	r8168_mac_ocp_modify(tp, 0xd420, 0x0fff, 0x047f);
> @@ -3715,7 +3715,7 @@ static void rtl_hw_start_8125_common(struct rtl8169_private *tp)
>  	r8168_mac_ocp_modify(tp, 0xc0b4, 0x0000, 0x000c);
>  	r8168_mac_ocp_modify(tp, 0xeb6a, 0x00ff, 0x0033);
>  	r8168_mac_ocp_modify(tp, 0xeb50, 0x03e0, 0x0040);
> -	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0030);
> +	r8168_mac_ocp_modify(tp, 0xe056, 0x00f0, 0x0000);
>  	r8168_mac_ocp_modify(tp, 0xe040, 0x1000, 0x0000);
>  	r8168_mac_ocp_modify(tp, 0xea1c, 0x0003, 0x0001);
>  	if (tp->mac_version == RTL_GIGA_MAC_VER_70 ||