Re: [Xen-devel] [PATCH 1 of 3] fix S3 suspend error

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 23/02/2009 04:46, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:

> I can't ensure my understanding exactly matching latest Linux
> S3 implementation which evolves quickly. But generally device
> drivers typically are allowed with two callbacks, one being invoked
> with irq enabled and the other with irq disabled, since some actions
> have such requirement. On the other side, system device class,
> such as ioapic, lapic, etc. are saved with irq disabled after other
> external devices.
> 
> Xen owns a few devices with most as system class, so for
> simplicity interrupt is disabled from start. It's not worthy of touching
> this flow for this simple spinlock issue, imo. :-)

Can you point out any core devices in modern Linux 2.6 which implement the
suspend_late() or *_noirq() callbacks (those appear to be the ones handled
in device_power_down() with IRQs disabled)? They seem very obsolete/legacy,
and looks to me like we could unconditionally *not* disable IRQs rather than
unconditionally disabling them.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel