lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 7 Mar 2009 22:53:31 -0500 (EST)
From:	Alan Stern <>
To:	"Rafael J. Wysocki" <>
cc:	Jeremy Fitzhardinge <>,
	LKML <>,
	Jesse Barnes <>,
	Thomas Gleixner <>,
	"Eric W. Biederman" <>,
	Ingo Molnar <>,
	Linus Torvalds <>,
	pm list <>,
	Arve Hjønnevåg <>
Subject: Re: [linux-pm] [RFC][PATCH][1/8] PM: Rework handling of interrupts
 during suspend-resume (rev. 5)

On Sat, 7 Mar 2009, Rafael J. Wysocki wrote:

> > One thing about this isn't clear: the distinction between "wake-up" 
> > interrupts and other interrupts.
> > 
> > In an ideal world, the only pending interrupts during sysdev_suspend
> > would be wake-up interrupts, because drivers would have prevented their
> > devices from generating any other kind of IRQ and would have done all
> > the necessary synchronization as part of their suspend (_not_
> > suspend_late) methods.  Thus there would be no need to distinguish
> > between wake-up and non-wake-up interrupts.
> > 
> > So perhaps you're worried about drivers that aren't sufficiently
> > clever.  Or is something deeper going on?
> Some drivers leave interrupts enabled during suspend on purpose and mark
> them as "wake-up interrupts" so that the platform can abort suspend if any
> of them is pending at the time the "enter suspend" hook is called (this doesn't
> happen on x86 AFAICS).
> However, after the $subject patch the CPU will ACK those interrupts if they
> happen between suspend_device_irqs() and local_irq_disable(), so the platform
> won't see them as pending.  Instead, they will have IRQ_PENDING set in
> desc->status, so we check if this is the case.

You didn't answer my question.  Why bother to distinguish between 
"wake-up" interrupts and non-"wake-up" interrupts?

In other words, why not simply abort the suspend if IRQ_PENDING is set
for _any_ interrupt during sysdev_suspend()?

Alan Stern

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists