Messages in this thread | | | Date | Tue, 04 Feb 2014 20:38:22 +0100 | From | Sebastian Hesselbarth <> | Subject | Re: [PATCH v2 0/5] net: phy: Ethernet PHY powerdown optimization |
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On 12/17/2013 08:43 PM, David Miller wrote: > From: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> > Date: Fri, 13 Dec 2013 10:20:24 +0100 > >> This is v2 of the ethernet PHY power optimization patches to reduce >> power consumption of network PHYs with link that are either unused or >> the corresponding netdev is down. >> >> Compared to the last version, this patch set drops a patch to disable >> unused PHYs after late initcall, as it is not compatible with a modular >> mdio bus [1]. I'll investigate different ways to have a modular mdio bus >> driver get notified when driver loading is done. >> >> Again, a branch with v2 applied to v3.13-rc2 can also be found at >> https://github.com/shesselba/linux-dove.git topic/ethphy-power-v2 >> >> [1] http://www.spinics.net/lists/arm-kernel/msg293028.html > > Series applied, thanks. >
David, Mungunthan, Florian,
as expected the above patches create a Linux to bootloader dependency that surfaces dumb bootloaders not initializing PHYs correctly.
Andrew has a Kirkwood based board that does not power-up and restart auto-negotiation on the powered down PHY after a warm restart. While this specific bootloader allows a soft-workaround by issuing the required PHY writes before accessing the interface, others may not.
I think we should allow the user to soft-disable the automatic power-down of PHYs, i.e. by exploiting a kernel parameter.
Do you have any preference for naming it? My call would be something like libphy.suspend_halted = [0,1] with 1 being the default.
Sebastian
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