linux-kernel - Re: [PATCH net-next v1 13/14] net: phy: nxp-c45-tja11xx: reset PCS if the link goes down

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: <d483be85-2d63-4b37-9cc3-f8924c53bd08@lunn.ch>
Date:   Fri, 16 Jun 2023 23:00:25 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     "Radu Pirea (NXP OSS)" <radu-nicolae.pirea@....nxp.com>
Cc:     hkallweit1@...il.com, linux@...linux.org.uk, davem@...emloft.net,
        edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
        richardcochran@...il.com, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, sebastian.tobuschat@....com
Subject: Re: [PATCH net-next v1 13/14] net: phy: nxp-c45-tja11xx: reset PCS
 if the link goes down

On Fri, Jun 16, 2023 at 04:53:22PM +0300, Radu Pirea (NXP OSS) wrote:
> During PTP testing on early TJA1120 engineering samples I observed that
> if the link is lost and recovered, the tx timestamps will be randomly
> lost. To avoid this HW issue, the PCS should be reseted.
> 
> Resetting the PCS will break the link and we should reset the PCS on
> LINK UP -> LINK DOWN transition, otherwise we will trigger and infinite
> loop of LINK UP -> LINK DOWN events.

> +static int tja1120_read_status(struct phy_device *phydev)
> +{
> +	unsigned int link = phydev->link;
> +	int ret;

Maybe consider using link_change_notify:

        /**
         * @link_change_notify: Called to inform a PHY device driver
         * when the core is about to change the link state. This
         * callback is supposed to be used as fixup hook for drivers
         * that need to take action when the link state
         * changes. Drivers are by no means allowed to mess with the
         * PHY device structure in their implementations.
         */
        void (*link_change_notify)(struct phy_device *dev);

Seems like a fixup to me.

      Andrew