Subject: Re: mvneta: SGMII fixed-link not so fixed

From: Stas Sergeev <[email-masked]>
Date: Mon, 14 Sep 2015 14:06:13 +0300

14.09.2015 13:32, Russell King - ARM Linux пишет:
> I've been bringing up the mainline kernel on a new board, which has
> an Marvell SoC with a mvneta interface connected to a Marvell DSA
> switch.  The DSA switch is a 88E6176.
>
> In the DT block for the interface, I specify:
>
> 	ethernet@... {
> 	        phy-mode = "sgmii";
> 		status = "okay";
>
> 		fixed-link {
> 			speed = <1000>;
> 			full-duplex;
> 		};
> 	};
>
> However, this doesn't work without patching mvneta to disable the
> autonegotiation and forcing the link up:
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 62e48bc0cb23..e1698731e429 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -1010,6 +1010,10 @@ static void mvneta_defaults_set(struct mvneta_port *pp)
>   		val |= MVNETA_GMAC_INBAND_AN_ENABLE |
>   		       MVNETA_GMAC_AN_SPEED_EN |
>   		       MVNETA_GMAC_AN_DUPLEX_EN;
> +		/* We appear to need the interface forced for DSA switches */
> +		val &= ~(MVNETA_GMAC_AN_DUPLEX_EN |
> +			 MVNETA_GMAC_AN_SPEED_EN);
> +		val |= MVNETA_GMAC_FORCE_LINK_PASS;
>   		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, val);
>   		val = mvreg_read(pp, MVNETA_GMAC_CLOCK_DIVIDER);
>   		val |= MVNETA_GMAC_1MS_CLOCK_ENABLE;
Hello Russell, just to make sure, aren't you missing this by any chance:
https://lkml.org/lkml/2015/7/20/710