netdev - Re: [PATCH] net: phy: realtek: convert RTL8226-CG to c45 only

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: <6e0e38b4-db64-4b63-ac36-4a432b762767@lunn.ch>
Date: Tue, 17 Jun 2025 17:36:16 +0200
From: Andrew Lunn <andrew@...n.ch>
To: Markus Stockhausen <markus.stockhausen@....de>
Cc: hkallweit1@...il.com, linux@...linux.org.uk, davem@...emloft.net,
	edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
	michael@...sekall.de, daniel@...rotopia.org, netdev@...r.kernel.org
Subject: Re: [PATCH] net: phy: realtek: convert RTL8226-CG to c45 only

On Tue, Jun 17, 2025 at 11:01:47AM -0400, Markus Stockhausen wrote:
> The RTL8226-CG can be found on devices like the Zyxel XGS1210-12. These
> are driven by a RTL9302B SoC that has active phy hardware polling in
> the background.

It would be a lot better to just turn that polling off.

> As soon as this is active and set to c45 most c22
> register accesses are blocked and will stop working. Convert the
> phy to a c45-only function set.
> 
> For documentation purposes some register extracts that where taken to
> verify proper detection.

Please could you show us the output from ethtool before/after.

>  		PHY_ID_MATCH_EXACT(0x001cc838),
>  		.name           = "RTL8226-CG 2.5Gbps PHY",
> -		.get_features   = rtl822x_get_features,

You can see this calls genphy_read_abilities(phydev) at the end, so
reading information about 10/100/1G speeds, using the standard C22
registers.

> -		.config_aneg    = rtl822x_config_aneg,
> -		.read_status    = rtl822x_read_status,
> -		.suspend        = genphy_suspend,
> -		.resume         = rtlgen_resume,
> +		.soft_reset     = rtl822x_c45_soft_reset,
> +		.get_features   = rtl822x_c45_get_features,

This only calls genphy_c45_pma_read_abilities(). So i expect 10/100/1G
is missing.

	Andrew