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  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]
Date:   Wed, 20 May 2020 09:03:52 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Dan Murphy <dmurphy@...com>, Andrew Lunn <andrew@...n.ch>
Cc:     hkallweit1@...il.com, davem@...emloft.net, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH net-next v2 3/4] dt-bindings: net: Add RGMII internal
 delay for DP83869



On 5/20/2020 8:56 AM, Dan Murphy wrote:
> Andrew
> 
> On 5/20/20 10:36 AM, Andrew Lunn wrote:
>>>> Hi Dan
>>>>
>>>> Having it required with PHY_INTERFACE_MODE_RGMII_ID or
>>>> PHY_INTERFACE_MODE_RGMII_RXID is pretty unusual. Normally these
>>>> properties are used to fine tune the delay, if the default of 2ns does
>>>> not work.
>>> Also if the MAC phy-mode is configured with RGMII-ID and no internal
>>> delay
>>> values defined wouldn't that be counter intuitive?
>> Most PHYs don't allow the delay to be fine tuned. You just pass for
>> example PHY_INTERFACE_MODE_RGMII_ID to the PHY driver and it enables a
>> 2ns delay. That is what people expect, and is documented.
> 
>> Being able to tune the delay is an optional extra, which some PHYs
>> support, but that is always above and beyond
>> PHY_INTERFACE_MODE_RGMII_ID.
> 
> I am interested in knowing where that is documented.  I want to RTM I
> grepped for a few different words but came up empty
> 
> Since this is a tuneable phy we need to program the ID.  2ns is the
> default value
> 
> Maybe I can change it from Required to Configurable or Used.

I do not think this is properly documented, it is an established
practice, but it should be clearly documented somewhere, I do not know
whether that belongs in the PHY Device Tree binding or if this belongs
to the PHY documentation.
-- 
Florian

Powered by blists - more mailing lists