netdev - Re: [PATCH net-next 1/2] net: phy: micrel: disable EEE on KSZ9477-type PHY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Z2WB7aOs0m4Kamfl@pengutronix.de>
Date: Fri, 20 Dec 2024 15:40:45 +0100
From: Oleksij Rempel <o.rempel@...gutronix.de>
To: Heiner Kallweit <hkallweit1@...il.com>
Cc: Russell King - ARM Linux <linux@...linux.org.uk>,
	Andrew Lunn <andrew@...n.ch>, Paolo Abeni <pabeni@...hat.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Eric Dumazet <edumazet@...gle.com>,
	David Miller <davem@...emloft.net>, Simon Horman <horms@...nel.org>,
	Woojung Huh <woojung.huh@...rochip.com>,
	Microchip Linux Driver Support <UNGLinuxDriver@...rochip.com>,
	Tim Harvey <tharvey@...eworks.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next 1/2] net: phy: micrel: disable EEE on
 KSZ9477-type PHY

On Fri, Dec 20, 2024 at 02:51:32PM +0100, Heiner Kallweit wrote:
> On several supported switches the integrated PHY's have buggy EEE.
> On the GBit-capable ones it's always the same type of PHY with PHY ID
> 0x00221631. So we can simplify the erratum handling by simply clearing
> phydev->supported_eee for this PHY type.
> 
> Note: The KSZ9477 PHY driver also covers e.g. the internal PHY of
>       KSZ9563 (ID: 0x00221637), which is unaffected by the EEE issue.
>       Therefore check for the exact PHY ID.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
> ---
>  drivers/net/phy/micrel.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 3ef508840..ece6d026e 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -1522,6 +1522,12 @@ static int ksz9477_get_features(struct phy_device *phydev)
>  	if (ret)
>  		return ret;
>  
> +	/* See KSZ9477 Errata DS80000754C Module 4 */
> +	if (phydev->phy_id == PHY_ID_KSZ9477) {
> +		linkmode_zero(phydev->supported_eee);
> +		return 0;
> +	}

Hm.. with this change, we won't be able to disable EEE. Zeroed
supported_eee will avoid writing to the EEE advertisement register.

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |