netdev - Re: [PATCH net-next v5] net: sfp: extend SMBus support

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 for Android: free password hash cracker in your pocket

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

Message-ID: <fe1bf7b6-d024-447c-a672-e84f4e77f8d7@lunn.ch>
Date: Fri, 16 Jan 2026 15:25:50 +0100
From: Andrew Lunn <andrew@...n.ch>
To: Maxime Chevallier <maxime.chevallier@...tlin.com>
Cc: Jonas Jelonek <jelonek.jonas@...il.com>,
	Russell King <linux@...linux.org.uk>,
	Heiner Kallweit <hkallweit1@...il.com>,
	"David S . Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Bjørn Mork <bjorn@...k.no>
Subject: Re: [PATCH net-next v5] net: sfp: extend SMBus support

> > Is there a use case for odd lengths? Apart from 1.
> 
> There's sfp_cotsworks_fixup_check() that does a 3-byte access :
> 	
> 	id->base.phys_id = SFF8024_ID_SFF_8472;
> 	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
> 	id->base.connector = SFF8024_CONNECTOR_LC;
> 	sfp_write(sfp, false, SFP_PHYS_ID, &id->base, 3);

Ah, fixing those broken cotsworks PHYs.

> It may be possible to turn that into 2 2-byte accesses if we write
> 
> 	id->base.phys_id = SFF8024_ID_SFF_8472;
> 	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
> 
> and then
> 
> 	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
> 	id->base.connector = SFF8024_CONNECTOR_LC;

Or just don't bother fixing the EEPROM, leave it broken, but use the
corrected values internally.

> But let's first figure-out if word-only smbus are really a thing

Some grep foo on /drivers/i2c/busses might answer that.

     Andrew