From: Florian Fainelli <f.fainelli@gmail.com>
To: Mason <slash.tmp@free.fr>, Andrew Lunn <andrew@lunn.ch>
Cc: netdev <netdev@vger.kernel.org>, David Miller <davem@davemloft.net>
Subject: Re: Waiting for the PHY to complete auto-negotiation
Date: Wed, 6 Dec 2017 15:00:07 -0800 [thread overview]
Message-ID: <31ba2a2d-99f4-64d7-b9e3-057cdaa1618c@gmail.com> (raw)
In-Reply-To: <b94d080e-1bc4-9e6f-3907-25c782809cbd@free.fr>
On 12/06/2017 11:25 AM, Mason wrote:
> On 06/12/2017 20:07, Andrew Lunn wrote:
>
>> By chip, you mean the Ethernet controller? Not the whole SoC?
>
> Doh! Yes. Let me rephrase.
>
> When we detect link down, we put the ethernet HW block in reset,
> and repeat initialization when the link comes back up.
>
> Hmmm, however, at the moment, I only reset on an administrative
> (user-requested) link down, i.e. through ndo_stop. I would probably
> have to handle cable unplug/replug events as well.
>
> Or just consider the quirk to make flow control too complicated
> to implement correctly...
I suppose your procedure is fine, but don't you have a better way to
resolve that by trying to place a special RX DMA ring entry that allows
your RX DMA not to be entirely stopped, but intentionally looped through
a buffer that you control? As long as you can stop the Ethernet MAC RX,
working with such a limitation is probably fine, but this really sounds
like a huge pain in the butt and a major HW flaw.
--
Florian
next prev parent reply other threads:[~2017-12-06 23:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-06 16:39 Waiting for the PHY to complete auto-negotiation Mason
2017-12-06 16:59 ` Andrew Lunn
2017-12-06 18:03 ` Mason
2017-12-06 18:26 ` Andrew Lunn
2017-12-06 19:00 ` Mason
2017-12-06 19:07 ` Andrew Lunn
2017-12-06 19:25 ` Mason
2017-12-06 23:00 ` Florian Fainelli [this message]
2017-12-07 16:17 ` Mason
2017-12-09 18:49 ` Florian Fainelli
2017-12-11 14:29 ` Mason
2017-12-11 14:36 ` Måns Rullgård
2017-12-11 14:47 ` Mason
2017-12-11 16:32 ` Måns Rullgård
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