From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth) Date: Mon, 10 Mar 2014 01:53:33 +0100 Subject: [PATCH] net: phy: Add sysfs attribute to prevent PHY suspend In-Reply-To: <20140309.204101.47552917508273123.davem@davemloft.net> References: <531CF864.9040406@gmail.com> <20140309.203001.1318893833441564547.davem@davemloft.net> <531D094C.1090205@gmail.com> <20140309.204101.47552917508273123.davem@davemloft.net> Message-ID: <531D0D0D.4050703@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/10/2014 01:41 AM, David Miller wrote: > From: Sebastian Hesselbarth > Date: Mon, 10 Mar 2014 01:37:32 +0100 > >> The mechanism is manual, no automatic way to determine it. > > We recognize BIOS and ACPI bugs and work around them, by looking at > version information and whatnot, so you really can't convince me that > something similar can't be done here perhaps in the platform code. Hmm, if the is a way to determine the version of that particual u-boot I'd be happy to exploit that information. But I honestly doubt that. Compared to u-boot bootloader and kernel interaction, BIOS and ACPI are well-defined protocols. I personally, would prefer everybody should update his broken bootloaders, but that will just not happen. Anyway, at least for the two boards in question, we know a bootloader workaround. The version does support user commands to re-enable the PHY by writing the corresponding registers. Unfortunately, the is a bug in phy_ethtool_get_wol that up to now, prevents most PHYs (without .wol callbacks) from being suspended. I wanted to get in a way to disable suspend before sending a fix. If you are that against a sysfs knob, I guess, we will just see how many more bootloaders are broken and some will not have a way to write PHY registers. Sebastian