Messages in this thread | | | Date | Fri, 03 Jul 2015 14:21:09 +0200 | From | Gregory CLEMENT <> | Subject | Re: [PATCH v2 2/4] ARM: mvebu: Add standby support |
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Hi Thomas,
On 03/07/2015 14:17, Thomas Petazzoni wrote: > Gregory, > > On Fri, 03 Jul 2015 13:39:49 +0200, Gregory CLEMENT wrote: > >> Having 2 initcall does not work because, there is a dependency between these >> 2 calls. And actually the suspend_ops is registered before the board specific >> hook. As soon as the suspend_ops is registered, mvebu_pm_valid() is called but >> at this point mvebu_board_pm_enter is NULL so PM_SUSPEND_MEM is not available. > > And? It will become available soon afterwards.
No it is called during boot and if the method is not there then it is no more available for the user. I made te test and with a cat on /sys/power/state I only got "freeze" and "standby" but not "mem".
Thanks,
Gregory
> >> All the complexity of the original patch was to allow registering a handler >> without needed to get the resource(gpio device) that are not available when using >> arch_initcall(). However the device_initcall_sync comes latter enough to >> get all the devices registered but it still happens before the late_initcall, >> so I will use this one and I will add a comment around it. > > I don't think we care about the order in which the initcalls are called. > > If the SoC level init call registering the suspend_ops gets called > first, then at the beginning there is only support for standby. The > support for suspend to RAM will be enabled once the board-level init > call gets called. > > If the board level init call is called first, then it will set > mvebu_board_pm_enter. It is not useful at this point. Until the SoC > level init call registers the suspend_ops. > > I believe that the ->valid() method of suspend_ops gets called when the > user actually enters the suspend state by writing to /sys/power/state. > And by that time, both init calls will have been called. > > Best regards, > > Thomas >
-- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
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