Re: [net-next] phylib: Add device reset GPIO support causes DSA MT7530 acquires reset-gpios fails

From: Florian Fainelli
Date: Mon Dec 18 2017 - 14:21:44 EST

On 12/18/2017 12:01 AM, Andrew Lunn wrote:
> Hi Sean
>> It probably can't. Because before the GPIO line is manipulated to reset,
>> certain power control should be handled such as power sources from
>> external PMIC to let devices actually enter the proper state.
>> So, I thought the kind of reset should be better controlled by the
>> specific driver, not by generic core.
> Yes, the driver should do it in that case.
> So we have a few choices:
> 1) Change the name of one of the properties
> 2) Make the new code look at the compatible string, any only apply a
> reset if it is a PHY.
> 3) Make the new code only hold the gpio when it needs it. Same for the
> driver, so that they both can reset the device.
> Any other ideas? Any preferences? 2) and 3) are probably simpler to
> do, less backwards compatibility issues. 3) potentially could cause
> issues when a device is reset in the wrong context, because of
> external PMIC etc. So i'm thinking 2).

We could also add some sort of flag that indicates whether the reset
should be managed by the core, or the driver, I would have to double
check there is not a chicken and egg problem and that the driver probe
is early enough this can happen...