linux-kernel - Re: [PATCH RFC net-next] net: phy: always set polarity

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Message-ID: <ZwBn-GJq3BovSJd4@makrotopia.org>
Date: Fri, 4 Oct 2024 23:11:04 +0100
From: Daniel Golle <daniel@...rotopia.org>
To: Andrew Lunn <andrew@...n.ch>
Cc: Heiner Kallweit <hkallweit1@...il.com>,
	Russell King <linux@...linux.org.uk>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Christian Marangi <ansuelsmth@...il.com>, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFC net-next] net: phy: always set polarity_modes if op
 is supported

On Fri, Oct 04, 2024 at 10:59:45PM +0200, Andrew Lunn wrote:
> On Fri, Oct 04, 2024 at 04:46:33PM +0100, Daniel Golle wrote:
> > Some PHYs drive LEDs active-low by default and polarity needs to be
> > configured in case the 'active-low' property is NOT set.
> > One way to achieve this without introducing an additional 'active-high'
> > property would be to always call the led_polarity_set operation if it
> > is supported by the phy driver.
> 
> It is a good idea to state why it is RFC. What comments do you want?
> 
> [...]
> I think adding an active-high property is probably the safest bet,
> even if it is more work.

Thank you. Exactly that was the clarification I was looking for:
If absence of "active-low" would mean "active-high" or should be
interpreted as "don't touch".

I'll add "active-high" as an additional property then, as I found out
that both, Aquantia and Intel/MaxLinear are technically speaking
active-low by default (ie. after reset) and what we need to set is a
property setting the LED to be driven active-high (ie. driving VDD
rather than GND) instead. I hope it's not too late to make this change
also for the Aquantia driver.