linux-kernel - Re: [PATCH v6 1/2] dt-bindings: net: Add FSD EQoS device tree bindings

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: <ffb13051-ab93-4729-8b98-20e278552673@lunn.ch>
Date: Fri, 14 Feb 2025 14:10:05 +0100
From: Andrew Lunn <andrew@...n.ch>
To: Swathi K S <swathi.ks@...sung.com>
Cc: krzk+dt@...nel.org, andrew+netdev@...n.ch, davem@...emloft.net,
	edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
	robh@...nel.org, conor+dt@...nel.org, richardcochran@...il.com,
	mcoquelin.stm32@...il.com, alexandre.torgue@...s.st.com,
	rmk+kernel@...linux.org.uk, netdev@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-stm32@...md-mailman.stormreply.com,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	'Pankaj Dubey' <pankaj.dubey@...sung.com>
Subject: Re: [PATCH v6 1/2] dt-bindings: net: Add FSD EQoS device tree
 bindings

On Fri, Feb 14, 2025 at 10:47:39AM +0530, Swathi K S wrote:
> 
> 
> > -----Original Message-----
> > From: Andrew Lunn <andrew@...n.ch>
> > Sent: 14 February 2025 05:50
> > To: Swathi K S <swathi.ks@...sung.com>
> > Cc: krzk+dt@...nel.org; andrew+netdev@...n.ch; davem@...emloft.net;
> > edumazet@...gle.com; kuba@...nel.org; pabeni@...hat.com;
> > robh@...nel.org; conor+dt@...nel.org; richardcochran@...il.com;
> > mcoquelin.stm32@...il.com; alexandre.torgue@...s.st.com;
> > rmk+kernel@...linux.org.uk; netdev@...r.kernel.org;
> > devicetree@...r.kernel.org; linux-stm32@...md-mailman.stormreply.com;
> > linux-arm-kernel@...ts.infradead.org; linux-kernel@...r.kernel.org
> > Subject: Re: [PATCH v6 1/2] dt-bindings: net: Add FSD EQoS device tree
> > bindings
> > 
> > > +  phy-mode:
> > > +    enum:
> > > +      - rgmii-id
> > 
> > phy-mode is normally a board property, in the .dts file, since the board
> might
> > decide to have extra long clock lines and so want 'rgmii'.
> > 
> > The only reason i can think of putting rgmii-id here is if the MAC only
> > supports 'rgmii-id', it is impossible to make it not add delays.
> > If that is true, a comment would be good.
> 
> 
> Hi Andrew,
> Thanks for reviewing.
> I think we already discussed this part some time back here [1]
> [1] :
> https://patchwork.kernel.org/project/linux-arm-kernel/patch/20230814112539.7
> 0453-2-sriranjani.p@...sung.com/#25879995
> Please do let me know if there is any other concern on this.

We partially discussed this in this thread.

As i said, what value you need here depends on the board design. The
PCB could provide the 2ns delay, in which case, 'rgmii' would be the
correct value to have in the board .dts file. Hence the binding should
not restrict the value of phy-mode to just rgmii-id. All 4 rmgii
values should be accepted.

The only reason you would force only rgmii-id is if the MAC/PHY pair
cannot do anything else. If that really is true, i would expect a
comment in the binding, and the MAC driver to return -EINVAL for
anything but rgmii-id.

	Andrew