Messages in this thread | | | Date | Sat, 7 Jul 2018 16:43:48 +0200 | From | Lukas Wunner <> | Subject | Re: [PATCH 5/5] thunderbolt: Add support for runtime PM |
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On Sat, Jul 07, 2018 at 05:25:53PM +0300, Mika Westerberg wrote: > On Sat, Jul 07, 2018 at 03:38:15PM +0200, Lukas Wunner wrote: > > You're setting pm_runtime_no_callbacks() on the domain. A side effect of > > setting this flag is that whenever the domain's device is runtime resumed, > > it's parent (the NHI) is *not* runtime resumed, see this comment in > > rpm_resume(): > > > > /* > > * See if we can skip waking up the parent. This is safe only if > > * power.no_callbacks is set, because otherwise we don't know whether > > * the resume will actually succeed. > > */ > > > > Above, you're runtime resuming the domain in boot_acl_show(). So if the > > NHI is runtime suspended while that sysfs attribute is accessed, it won't > > be runtime resumed. Is that actually what you want? > > No, it should be runtime resumed when domain is. Looking at the code in > question bit more deeper: [snip] > So skipping waking the parent can only happen if any of the following > conditions are true: > > - Parent has runtime PM disabled > - Parent has ignore_children set > - Parent is already resumed > > As far I can tell there can't be situation you describe that the parent would > not be runtime resumed when the domain is.
Okay, missed that.
Then why aren't you using pm_runtime_no_callbacks() on switches as well? Wouldn't that obviate the need to declare those empty runtime PM callbacks?
> > BTW, what's the purpose of nhi_enable_int_throttling()? > > It changes how fast interrupts get delivered and when to start throttling. > Mostly needed in P2P functionality (but should not do any harm for control > channel traffic). See also 8c6bba10fb92 ("thunderbolt: Configure interrupt > throttling for all interrupts").
Understood, thanks.
Lukas
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