From: "Ardelean, Alexandru" <alexandru.Ardelean@analog.com>
To: "andrew@lunn.ch" <andrew@lunn.ch>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
"hkallweit1@gmail.com" <hkallweit1@gmail.com>
Subject: Re: [PATCH v2 1/2] ethtool: implement Energy Detect Powerdown support via phy-tunable
Date: Thu, 5 Sep 2019 06:25:13 +0000 [thread overview]
Message-ID: <361eb94a4da73d1fa21893e8e294639f0fc0bcd2.camel@analog.com> (raw)
In-Reply-To: <20190904195357.GA21264@lunn.ch>
On Wed, 2019-09-04 at 21:53 +0200, Andrew Lunn wrote:
> [External]
>
> On Wed, Sep 04, 2019 at 07:23:21PM +0300, Alexandru Ardelean wrote:
>
> Hi Alexandru
>
> Somewhere we need a comment stating what EDPD means. Here would be a
> good place.
ack
>
> > +#define ETHTOOL_PHY_EDPD_DFLT_TX_INTERVAL 0x7fff
> > +#define ETHTOOL_PHY_EDPD_NO_TX 0x8000
> > +#define ETHTOOL_PHY_EDPD_DISABLE 0
>
> I think you are passing a u16. So why not 0xfffe and 0xffff? We also
> need to make it clear what the units are for interval. This file
I initially thought about keeping this u8 and going with 0xff & 0xfe.
But 254 or 253 could be too small to specify the value of an interval.
Also (maybe due ti all the coding-patterns that I saw over the course of some time), make me feel that I should add a
flag somewhere.
Bottom line is: 0xfffe and 0xffff also work from my side, if it is acceptable (by the community).
Another approach I considered, was to maybe have this EDPD just do enable & disable (which is sufficient for the `adin`
PHY & `micrel` as well).
That would mean that if we would ever want to configure the TX interval (in the future), we would need an extra PHY-
tunable parameter just for that; because changing the enable/disable behavior would be dangerous.
And also, deferring the TX-interval configuration, does not sound like good design/pattern, since it can allow for tons
of PHY-tunable parameters for every little knob.
> specifies the contract between the kernel and user space. So we need
> to clearly define what we mean here. Lots of comments are better than
> no comments.
Will come back with more comments.
>
> Andrew
next prev parent reply other threads:[~2019-09-05 6:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 16:23 [PATCH v2 0/2] ethtool: implement Energy Detect Powerdown support via phy-tunable Alexandru Ardelean
2019-09-04 16:23 ` [PATCH v2 1/2] " Alexandru Ardelean
2019-09-04 19:53 ` Andrew Lunn
2019-09-05 6:25 ` Ardelean, Alexandru [this message]
2019-09-05 17:23 ` Florian Fainelli
2019-09-04 16:23 ` [PATCH v2 2/2] net: phy: adin: implement Energy Detect Powerdown mode " Alexandru Ardelean
2019-09-04 20:03 ` Andrew Lunn
2019-09-05 6:32 ` Ardelean, Alexandru
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