Subject: Re: [PATCH net-next 1/1] e1000e: Enable Link Partner Advertised Support

From: Andrew Lunn <[email-masked]>
Date: Wed, 4 Jan 2023 01:47:01 +0100

> --- a/drivers/net/ethernet/intel/e1000e/phy.c
> +++ b/drivers/net/ethernet/intel/e1000e/phy.c
> @@ -2,6 +2,7 @@
>  /* Copyright(c) 1999 - 2018 Intel Corporation. */
>  
>  #include "e1000.h"
> +#include <linux/ethtool.h>
>  
>  static s32 e1000_wait_autoneg(struct e1000_hw *hw);
>  static s32 e1000_access_phy_wakeup_reg_bm(struct e1000_hw *hw, u32 offset,
> @@ -1011,6 +1012,8 @@ static s32 e1000_phy_setup_autoneg(struct e1000_hw *hw)
>  		 */
>  		mii_autoneg_adv_reg &=
>  		    ~(ADVERTISE_PAUSE_ASYM | ADVERTISE_PAUSE_CAP);
> +		phy->autoneg_advertised &=
> +		    ~(ADVERTISED_Pause | ADVERTISED_Asym_Pause);
>  		break;
>  	case e1000_fc_rx_pause:
>  		/* Rx Flow control is enabled, and Tx Flow control is
> @@ -1024,6 +1027,8 @@ static s32 e1000_phy_setup_autoneg(struct e1000_hw *hw)
>  		 */
>  		mii_autoneg_adv_reg |=
>  		    (ADVERTISE_PAUSE_ASYM | ADVERTISE_PAUSE_CAP);
> +		phy->autoneg_advertised |=
> +		    (ADVERTISED_Pause | ADVERTISED_Asym_Pause);
>  		break;
>  	case e1000_fc_tx_pause:
>  		/* Tx Flow control is enabled, and Rx Flow control is
> @@ -1031,6 +1036,8 @@ static s32 e1000_phy_setup_autoneg(struct e1000_hw *hw)
>  		 */
>  		mii_autoneg_adv_reg |= ADVERTISE_PAUSE_ASYM;
>  		mii_autoneg_adv_reg &= ~ADVERTISE_PAUSE_CAP;
> +		phy->autoneg_advertised |= ADVERTISED_Asym_Pause;
> +		phy->autoneg_advertised &= ~ADVERTISED_Pause;
>  		break;
>  	case e1000_fc_full:
>  		/* Flow control (both Rx and Tx) is enabled by a software
> @@ -1038,6 +1045,8 @@ static s32 e1000_phy_setup_autoneg(struct e1000_hw *hw)
>  		 */
>  		mii_autoneg_adv_reg |=
>  		    (ADVERTISE_PAUSE_ASYM | ADVERTISE_PAUSE_CAP);
> +		phy->autoneg_advertised |=
> +		    (ADVERTISED_Pause | ADVERTISED_Asym_Pause);
>  		break;
>  	default:
>  		e_dbg("Flow control param set incorrectly\n");
> -- 

I don't know this driver at all. What i don't see anywhere here is
using the results of the pause auto-neg. Is there some code somewhere
that looks at the local and link peer advertising values and runs a
resolve algorithm to determine what pause should be used, and program
it into the MAC?

    Andrew