Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932198AbaBDTid (ORCPT ); Tue, 4 Feb 2014 14:38:33 -0500 Received: from mail-ea0-f174.google.com ([209.85.215.174]:64020 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828AbaBDTia (ORCPT ); Tue, 4 Feb 2014 14:38:30 -0500 Message-ID: <52F141AE.8010402@gmail.com> Date: Tue, 04 Feb 2014 20:38:22 +0100 From: Sebastian Hesselbarth User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 To: David Miller CC: f.fainelli@gmail.com, mugunthanvnm@ti.com, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Andrew Lunn Subject: Re: [PATCH v2 0/5] net: phy: Ethernet PHY powerdown optimization References: <1386513631-11284-1-git-send-email-sebastian.hesselbarth@gmail.com> <1386926429-28818-1-git-send-email-sebastian.hesselbarth@gmail.com> <20131217.144313.1563516273987934449.davem@davemloft.net> In-Reply-To: <20131217.144313.1563516273987934449.davem@davemloft.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/17/2013 08:43 PM, David Miller wrote: > From: Sebastian Hesselbarth > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/