Re: Waiting for the PHY to complete auto-negotiation

On 12/06/2017 11:25 AM, Mason wrote:

On 06/12/2017 20:07, Andrew Lunn wrote:

quoted

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