Messages in this thread | | | Date | Thu, 7 Feb 2019 15:06:38 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH] drivers: base: add support to skip power management in device/driver model |
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On Thu, Feb 07, 2019 at 03:29:07PM +0100, Ulf Hansson wrote: > On Thu, 7 Feb 2019 at 11:36, Sudeep Holla <sudeep.holla@arm.com> wrote:
[..]
> > > > May be, but as mentioned above we can't really. Also this change will > > help to avoid creating unnecessary power sysfs which is mainly runtime > > pm related for some of the devices created. CPU/caches was just one > > example which triggered this, but this can be more useful. We can avoid > > adding them to dpm list. > > Well, to me the approach you suggest sounds prone to errors and I am > afraid people may abuse it. Moreover, I don't know if there is other > problems with it, let's see what Rafael thinks about it. >
Sorry, I should have put reference to earlier discussion that led to this patch. For your reference: [1]
> Instead I think we should make the PM core to deal with this scenario, > as all it boils down to, is to allow a device to be unregistered and > registered during system suspend/resume, with a parent device that is > "persistent" during the sequence. >
OK
> Perhaps we could even just drop the corresponding printed warning, > "cache: parent cpu1 should not be sleeping", in device_pm_add() as I > wonder if it's really a necessary print. > Indeed, I was ignoring knowing that it's harmless. But more people started to complain, and Rafael suggested this which I agree as we have several pseudo devices created in the kernel that we can bypass some of these pm handling knowing we won't need it.
-- Regards, Sudeep
[1] https://lkml.org/lkml/2019/1/30/1078
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