Messages in this thread | | | Date | Tue, 26 Jul 2022 15:54:30 +0100 | From | Sudeep Holla <> | Subject | Re: [-next] Lockdep warnings |
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On Tue, Jul 26, 2022 at 03:44:31PM +0100, Mark Rutland wrote: > On Tue, Jul 26, 2022 at 11:41:34AM +0100, Sudeep Holla wrote: > > I was seeing the below lockdep warnings on my arm64 Juno development > > platform almost 2 weeks back with -next. I wanted to check for similar > > reports before post and forgot. > > [...] > > > However I don't see the above warning with the latest -next. When I tried > > yesterday's -next now, I see a different warning. Not sure if they are > > related. I haven't tried to bisect. > > > > --->8 > > ============================= > > [ BUG: Invalid wait context ] > > 5.19.0-rc8-next-20220725 #38 Not tainted > > ----------------------------- > > swapper/0/0 is trying to lock: > > (&drvdata->spinlock){....}-{3:3}, at: cti_cpu_pm_notify+0x54/0x114 > > Hmmm... do you have CONFIG_PROVE_RAW_LOCK_NESTING enabled? >
Yes.
> IIUC that should be {2:2} otherwise... > > > other info that might help us debug this: > > context-{5:5} > > 1 lock held by swapper/0/0: > > #0: (cpu_pm_notifier.lock){....}-{2:2}, at: cpu_pm_enter+0x2c/0x80 > > ... and this is telling us that we're trying to take a regular spinlock under a > raw spinlock, which is not as intended. > > The Kconfig text notes: > > NOTE: There are known nesting problems. So if you enable this > option expect lockdep splats until these problems have been fully > addressed which is work in progress. This config switch allows to > identify and analyze these problems. It will be removed and the > check permanently enabled once the main issues have been fixed. >
Ah, I hadn't seen or read this. Thanks for digging this and sharing. Sorry for the noise. Good I got to know this limitation, will try to remember this.
Thanks again for your time Mark.
-- Regards, Sudeep
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