linux-kernel - Re: [PATCH v2 1/2] net: phy: adin: disable diag clock & disable standby mode in config

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]

Date:   Sat, 24 Oct 2020 00:43:36 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     Alexandru Ardelean <alexandru.ardelean@...log.com>
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        hkallweit1@...il.com, linux@...linux.org.uk, davem@...emloft.net,
        kuba@...nel.org, ardeleanalex@...il.com
Subject: Re: [PATCH v2 1/2] net: phy: adin: disable diag clock & disable
 standby mode in config_aneg

On Thu, Oct 22, 2020 at 10:45:50AM +0300, Alexandru Ardelean wrote:
> When the PHY powers up, the diagnostics clock isn't enabled (bit 2 in
> register PHY_CTRL_1 (0x0012)).
> Also, the PHY is not in standby mode, so bit 13 in PHY_CTRL_3 (0x0017) is
> always set at power up.
> 
> The standby mode and the diagnostics clock are both meant to be for the
> cable diagnostics feature of the PHY (in phylib this would be equivalent to
> the cable-test support), and for the frame-generator feature of the PHY.
> 
> In standby mode, the PHY doesn't negotiate links or manage links.
> 
> To use the cable diagnostics/test (or frame-generator), the PHY must be
> first set in standby mode, so that the link operation doesn't interfere.
> Then, the diagnostics clock must be enabled.
> 
> For the cable-test feature, when the operation finishes, the PHY goes into
> PHY_UP state, and the config_aneg hook is called.
> 
> For the ADIN PHY, we need to make sure that during autonegotiation
> configuration/setup the PHY is removed from standby mode and the
> diagnostics clock is disabled, so that normal operation is resumed.
> 
> This change does that by moving the set of the ADIN1300_LINKING_EN bit (2)
> in the config_aneg (to disable standby mode).
> Previously, this was set in the downshift setup, because the downshift
> retry value and the ADIN1300_LINKING_EN are in the same register.
> 
> And the ADIN1300_DIAG_CLK_EN bit (13) is cleared, to disable the
> diagnostics clock.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@...log.com>

Reviewed-by: Andrew Lunn <andrew@...n.ch>

    Andrew