Messages in this thread | | | From | Kai-Heng Feng <> | Date | Fri, 21 Jan 2022 22:17:18 +0800 | Subject | Re: [PATCH v2] net: phy: marvell: Honor phy LED set by system firmware on a Dell hardware |
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On Fri, Jan 21, 2022 at 9:22 PM Andrew Lunn <andrew@lunn.ch> wrote: > > On Fri, Jan 21, 2022 at 12:01:35PM +0800, Kai-Heng Feng wrote: > > On Thu, Jan 20, 2022 at 10:26 PM Andrew Lunn <andrew@lunn.ch> wrote: > > > > > > On Thu, Jan 20, 2022 at 01:19:29PM +0800, Kai-Heng Feng wrote: > > > > BIOS on Dell Edge Gateway 3200 already makes its own phy LED setting, so > > > > instead of setting another value, keep it untouched and restore the saved > > > > value on system resume. > > > > > > > > Introduce config_led() callback in phy_driver() to make the implemtation > > > > generic. > > > > > > I'm also wondering if we need to take a step back here and get the > > > ACPI guys involved. I don't know much about ACPI, but shouldn't it > > > provide a control method to configure the PHYs LEDs? > > > > > > We already have the basics for defining a PHY in ACPI. See: > > > > > > https://www.kernel.org/doc/html/latest/firmware-guide/acpi/dsd/phy.html > > > > These properties seem to come from device-tree. > > They are similar to what DT has, but expressed in an ACPI way. DT has > been used with PHY drivers for a long time, but ACPI is new. The ACPI > standard also says nothing about PHYs. So Linux has defined its own > properties, which we expect all ACPI machine to use. According to the > ACPI maintainers, this is within the ACPI standard. Maybe at some > point somebody will submit the current definitions to the standards > body for approval, or maybe the standard will do something completely > different, but for the moment, this is what we have, and what you > should use.
Right, so we can add a new property, document it, and just use it? Maybe others will use the new property once we set the precedence?
> > > > so you could extend this to include a method to configure the LEDs for > > > a specific PHY. > > > > How to add new properties? Is it required to add new properties to > > both DT and ACPI? > > Since all you are adding is a boolean, 'Don't touch the PHY LED > configuration', it should be easy to do for both.
If adding a brand new property is acceptable, let me discuss it the vendor.
> > What is interesting for Marvell PHYs is WoL, which is part of LED > configuration. I've not checked, but i guess there are other PHYs > which reuse LED output for a WoL interrupt. So it needs to be clearly > defined if we expect the BIOS to also correctly configure WoL, or if > Linux is responsible for configuring WoL, even though it means > changing the LED configuration.
How about what Heiner proposed? Maybe we should leave the LED as is, and restore it on system resume?
Kai-Heng
> > Andrew
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