linux-kernel - Re: [PATCH net-next v3 2/3] net: phy: micrel: add option to keep the preamble before sfd for KSZ9131

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: <949e9bc1-9016-45e6-8b94-d1160dc51c3d@lunn.ch>
Date: Thu, 22 Jan 2026 14:08:56 +0100
From: Andrew Lunn <andrew@...n.ch>
To: Stefan Eichenberger <eichest@...il.com>
Cc: andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com,
	kuba@...nel.org, pabeni@...hat.com, mcoquelin.stm32@...il.com,
	alexandre.torgue@...s.st.com, shawnguo@...nel.org,
	s.hauer@...gutronix.de, kernel@...gutronix.de, festevam@...il.com,
	hkallweit1@...il.com, linux@...linux.org.uk,
	linux-stm32@...md-mailman.stormreply.com,
	maxime.chevallier@...tlin.com, francesco.dolcini@...adex.com,
	netdev@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	imx@...ts.linux.dev, linux-kernel@...r.kernel.org,
	Stefan Eichenberger <stefan.eichenberger@...adex.com>
Subject: Re: [PATCH net-next v3 2/3] net: phy: micrel: add option to keep the
 preamble before sfd for KSZ9131

On Tue, Jan 20, 2026 at 09:30:03PM +0100, Stefan Eichenberger wrote:
> From: Stefan Eichenberger <stefan.eichenberger@...adex.com>
> 
> If the PHY_F_KEEP_PREAMBLE_BEFORE_SFD flag is set in the
> phy_device::dev_flags field, the preamble will be kept before the start
> frame delimiter (SFD) on the KSZ9131 PHY. This flag is not officially
> documented by Micrel. However, information provided by NXP and Micrel
> indicates that this flag ensures the PHY sends the full preamble instead
> of removing it. The full discussion can be found on the NXP forum:
> https://community.nxp.com/t5/i-MX-Processors/iMX8MP-eqos-not-working-for-10base-t/m-p/2151032
> 
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@...adex.com>

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

    Andrew