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Date:   Thu, 15 Aug 2019 09:37:06 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Woody Suwalski <terraluna977@gmail.com>
cc:     LKML <linux-kernel@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: Kernel 5.3.x, 5.2.2+: VMware player suspend on 64/32 bit
 guests
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Woody,

On Tue, 13 Aug 2019, Woody Suwalski wrote:
> On Mon, Aug 12, 2019 at 1:24 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> > The ACPI handler is not the culprit. This is either an emulation bug or
> > something really strange. Can you please use a WARN_ON() if the loop is
> > exited via the timeout so we can see in which context this happens?
> >
>
> B. On 5.3-rc4 problem is gone. I guess it is overall good sign.

Now the interesting question is what changed between 5.3-rc3 and
5.3-rc4. Could you please try to bisect that?

> C. To recreate problem I went back to 5.2.4. The WARN_ON trace shows
> (in reverse):

Next time you can spare yourself the work to reverse the stack trace. We
are all used to read it the other way round :)

> entry_SYSCALL_64_after_hwframe
> do_syscall_64
> ksys_write
> vfs_write
> kernfs_fop_write
> state_store
> pm_suspend.cold.3
> suspend_devices_and_enter
> dpm_suspend_noirq
> suspend_device_irqs
> ?ktime_get
> ?synchronize
> synchronize_irq
> __synchronize_hardirq.cold.9

dpm_suspend_noirq() is called with all CPUs online and interrupts
enabled. In that case an interrupt pending in IRR does not make any sense
at all. Confused.

Thanks,

	tglx