RE: [PATCH net-next 3/3] net: fec: reset phy on resume after power-up

-----Original Message-----
From: Francesco Dolcini <redacted>
Sent: 2021年12月15日 19:02
To: Andrew Lunn <andrew@lunn.ch>; Russell King (Oracle)
[off-list ref]; Joakim Zhang [off-list ref]
Cc: Russell King (Oracle) <linux@armlinux.org.uk>; Francesco Dolcini
[off-list ref]; Philippe Schenker
[off-list ref]; netdev@vger.kernel.org; Joakim Zhang
[off-list ref]; David S . Miller [off-list ref];
Heiner Kallweit [off-list ref]; Jakub Kicinski [off-list ref];
Fabio Estevam [off-list ref]; linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 3/3] net: fec: reset phy on resume after
power-up

[...]

On Wed, Dec 15, 2021 at 10:25:14AM +0000, Joakim Zhang wrote:

quoted

As I mentioned before, both mac and phylib have not taken PHY reset
into consideration during system suspend/resume scenario. As Andrew
suggested, you could move this into phy driver suspend function, this
is a corner case. One point I don't understand, why do you reject to
assert reset signal during system suspended?

See my answer to Andrew above, in short asserting the reset without
disabling the regulator will create a regression on the power consumption.

As I can see, when system suspended, PHY is totally powered down, since you disable the 
regulator. At this situation, if you assert reset signal, you mean it will increase the power
consumption? PHY is totally powered down, why assert reset signal still affect PHY? 
 
Best Regards,
Joakim Zhang