From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth) Date: Mon, 10 Mar 2014 01:37:32 +0100 Subject: [PATCH] net: phy: Add sysfs attribute to prevent PHY suspend In-Reply-To: <20140309.203001.1318893833441564547.davem@davemloft.net> References: <1394192092-27461-1-git-send-email-sebastian.hesselbarth@gmail.com> <20140309.191235.1047481546773873653.davem@davemloft.net> <531CF864.9040406@gmail.com> <20140309.203001.1318893833441564547.davem@davemloft.net> Message-ID: <531D094C.1090205@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/10/2014 01:30 AM, David Miller wrote: > From: Sebastian Hesselbarth > Date: Mon, 10 Mar 2014 00:25:24 +0100 > >> There is no way to determine if a bootloader is broken or not. The >> sysfs knob allows to provide a use case based decision. Of course, >> we can invent some freaky device tree property but that the DT >> maintainers will not like either. > > My point is that whatever mechanism is used to "decide" that the sysfs > knob gets set, can also be used to "decide" that a DT property is > instantiated in the device tree. The mechanism is manual, no automatic way to determine it. I understand your point, but DT maintainers will argue here that DT is to describe HW not SW. And a badly written bootloader initialization routine for a PHY is SW. Also, this will force us to maintain two sets of DT files for each affected board: one for those with broken bootloader and one for those with an updated, fixed bootloader. And of course, the broken bootloaders are from pre-DT times and cannot even set that property but require the user to pick the right DT. If you are still against a sysfs knob, I see no way to provide a user accessible way to prevent the PHY to be suspended. And the user is the only reliable instance to decide not to suspend it. Sebastian