From: Florian Fainelli <f.fainelli@gmail.com>
To: Mugunthan V N <mugunthanvnm@ti.com>
Cc: netdev <netdev@vger.kernel.org>, David Miller <davem@davemloft.net>
Subject: Re: phy link status not stable
Date: Tue, 16 Sep 2014 10:09:36 -0700 [thread overview]
Message-ID: <CAGVrzcZ4BPJ-6t81vevb2g7jMqRmeCnGfEOhZA2gLO7qawZvPg@mail.gmail.com> (raw)
In-Reply-To: <541864D0.7080803@ti.com>
2014-09-16 9:26 GMT-07:00 Mugunthan V N <mugunthanvnm@ti.com>:
> Hi
>
> While doing ifdown/ifup test, phy link up status is very much delayed
> and also link up/down comes alternatively without physical link changes
> which leads to ifup failure. in v3.12 internal tree there is no failure.
> Pasting the logs below.
Assuming your driver calls phy_start() and phy_stop() from the
ndo_open() resp. ndo_stop() functions, these function calls are not
synchronous, as in they do not wait for the link to go UP resp. DOWN
before returning. The PHY state machine gets programmed to a new state
from phy_start() resp. phy_stop() and the next workqueue execution
will proceed with an actual state change.
>
> root@am437x-evm:~# ifup eth0
> [ 652.633204] net eth0: initializing cpsw version 1.15 (0)
> [ 652.717428] net eth0: phy found : id is : 0x221622
> udhcpc (v1.20.2) started
> Sending discover...
> Sending discover...
> [ 658.717859] cpsw 4a100000.ethernet eth0: Link is Up - 1Gbps/Full -
> flow control rx/tx
> Sending discover...
> [ 660.717894] cpsw 4a100000.ethernet eth0: Link is Down
> [ 661.717937] cpsw 4a100000.ethernet eth0: Link is Up - 1Gbps/Full -
> flow control rx/tx
> No lease, failing
> root@am437x-evm:~# udhcpc
> udhcpc (v1.20.2) started
> Sending discover...
> Sending select for 172.24.190.6...
> Lease of 172.24.190.6 obtained, lease time 3600
> /etc/udhcpc.d/50default: Adding DNS 192.0.2.2
> /etc/udhcpc.d/50default: Adding DNS 192.0.2.3
> root@am437x-evm:~#
>
> Is this a known issue or any pointers where to look for clues?
This is not a known issue AFAICT, is the link really flapping? Not
sure if [1] could explain what you are seeing?
[1]: http://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=95e8b10393f88a0db88d97e9d1953f01c854315a
could ex
>
> Setup: TI-AM437x EVM
> Phy: Micrel KSZ9031 Gigabit PHY
>
> Thanks,
> Mugunthan V N
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Florian
prev parent reply other threads:[~2014-09-16 17:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-16 16:26 phy link status not stable Mugunthan V N
2014-09-16 17:09 ` Florian Fainelli [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=CAGVrzcZ4BPJ-6t81vevb2g7jMqRmeCnGfEOhZA2gLO7qawZvPg@mail.gmail.com \
--to=f.fainelli@gmail.com \
--cc=davem@davemloft.net \
--cc=mugunthanvnm@ti.com \
--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).