From: Andrew Lunn <andrew@lunn.ch>
To: Helmut Grohne <helmut.grohne@intenta.de>
Cc: netdev@vger.kernel.org
Subject: Re: correct use of PHY_INTERFACE_MODE_RGMII{,_TXID,_RXID,_ID}
Date: Wed, 10 Jun 2020 22:12:24 +0200 [thread overview]
Message-ID: <20200610201224.GC19869@lunn.ch> (raw)
In-Reply-To: <20200610081236.GA31659@laureti-dev>
On Wed, Jun 10, 2020 at 10:12:37AM +0200, Helmut Grohne wrote:
> Hi,
>
> I've been trying to write a dt for a board and got quite confused about
> the RGMII delays. That's why I looked into it and got even more confused
> by what I found. Different drivers handle this quite differently. Let me
> summarize.
Hi Helmut
In general, in DT, put what you want the PHY to do. If the PCB does
not add the delay, use rgmii-id. If the PCB does add the delay, then
use rgmii.
It is quite confusing, we have had bugs, and some drivers just do odd
things. In general, the MAC should not add delays. The PHY should add
delays, based on what is passed via DT. This assumes the PHY actually
implements the delays, which most PHYs do.
What exact hardware are you using?
Andrew
next prev parent reply other threads:[~2020-06-10 20:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 8:12 correct use of PHY_INTERFACE_MODE_RGMII{,_TXID,_RXID,_ID} Helmut Grohne
2020-06-10 9:10 ` Ioana Ciornei
2020-06-10 10:34 ` Helmut Grohne
2020-06-10 11:44 ` Ioana Ciornei
2020-06-10 20:12 ` Andrew Lunn [this message]
2020-06-10 20:40 ` Florian Fainelli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200610201224.GC19869@lunn.ch \
--to=andrew@lunn.ch \
--cc=helmut.grohne@intenta.de \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).