linux-kernel - Re: [PATCH 06/16] net: phy: adin: support PHY mode converters

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: <20190805145105.GN24275@lunn.ch>
Date:   Mon, 5 Aug 2019 16:51:05 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     Alexandru Ardelean <alexandru.ardelean@...log.com>
Cc:     netdev@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, davem@...emloft.net,
        robh+dt@...nel.org, mark.rutland@....com, f.fainelli@...il.com,
        hkallweit1@...il.com
Subject: Re: [PATCH 06/16] net: phy: adin: support PHY mode converters

On Mon, Aug 05, 2019 at 07:54:43PM +0300, Alexandru Ardelean wrote:
> Sometimes, the connection between a MAC and PHY is done via a
> mode/interface converter. An example is a GMII-to-RGMII converter, which
> would mean that the MAC operates in GMII mode while the PHY operates in
> RGMII. In this case there is a discrepancy between what the MAC expects &
> what the PHY expects and both need to be configured in their respective
> modes.
> 
> Sometimes, this converter is specified via a board/system configuration (in
> the device-tree for example). But, other times it can be left unspecified.
> The use of these converters is common in boards that have FPGA on them.
> 
> This patch also adds support for a `adi,phy-mode-internal` property that
> can be used in these (implicit convert) cases. The internal PHY mode will
> be used to specify the correct register settings for the PHY.
> 
> `fwnode_handle` is used, since this property may be specified via ACPI as
> well in other setups, but testing has been done in DT context.

Looking at the patch, you seems to assume phy-mode is what the MAC is
using? That seems rather odd, given the name. It seems like a better
solution would be to add a mac-mode, which the MAC uses to configure
its side of the link. The MAC driver would then implement this
property.

I don't see a need for this. phy-mode indicates what the PHY should
use. End of story.

     Andrew