From: stefan.wahren@i2se•com (Stefan Wahren)
To: linux-arm-kernel@lists•infradead.org
Subject: net/fec: Unable to get a permanent link when connecting to a PC
Date: Mon, 22 Sep 2014 10:06:14 +0200 [thread overview]
Message-ID: <541FD876.4090109@i2se.com> (raw)
In-Reply-To: <1XUuZV-0zjkn20@fwd01.aul.t-online.de>
Am 19.09.2014 um 11:33 schrieb to-fleischer at t-online.de:
> I have an i.MX283 board with a KSZ8081 PHY that is connected to the controller
> via RMII. The PHY's interrupt line is currently unused, but connected to the
> controller. The board runs the linux version 3.17-rc5.
> When I connect the board directly to a PC the ethernet link goes up and a second
> later down. This is repeated again and again.
> After some investigation I found that this is caused by the reset of the FEC at
> the begin of fec_restart() that is called by fec_enet_adjust_link() if the link
> is up.
> Due to the reset the mode is set to MII. After switching back to RMII the PHY
> seems to restart the autonegotiation. Since this takes a while the next call of
> phy_state_machine() detects that the link is down.
> It would work, if the reset in fec_restart is avoided for the case that the link
> goes up and the fec is still stopped.
>
> Its quite remarkable that this issue does not occur if I connect the board to a
> switch or if I use the PHY's interrupt line.
>
> What do you think?
>
> Best Regards,
> Torsten Fleischer
>
Add netdev list
Best regards
Stefan Wahren
prev parent reply other threads:[~2014-09-22 8:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-19 9:33 net/fec: Unable to get a permanent link when connecting to a PC to-fleischer at t-online.de
2014-09-22 8:06 ` Stefan Wahren [this message]
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=541FD876.4090109@i2se.com \
--to=stefan.wahren@i2se$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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