Re: [Bugfix 1/2] x86, irq, PCI: Keep IRQ assignment for PCI devices during suspend/hibernation

Borislav Petkov
2014-08-05T18:37:40Z

On Tue, Aug 05, 2014 at 11:26:17AM +0800, Jiang Liu wrote:
> Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins.
> We need to keep IRQ assignment for PCI devices during suspend/hibernation,
> otherwise it may cause failure of suspend/hibernation due to:
> 1) Device driver calls pci_enable_device() to allocate an IRQ number
> and register interrupt handler on the returned IRQ.
> 2) Device driver's suspend callback calls pci_disable_device() and
> release assigned IRQ in turn.
> 3) Device driver's resume callback calls pci_enable_device() to
> allocate IRQ number again. A different IRQ number may be assigned
> by IOAPIC driver this time.
> 4) Now the hardware delivers interrupt to the new IRQ but interrupt
> handler is still registered against the old IRQ, so it breaks
> suspend/hibernation.
>
> To fix this issue, we keep IRQ assignment during suspend/hibernation.
> Flag pci_dev.dev.power.is_prepared is used to detect that
> pci_disable_device() is called during suspend/hibernation.
>
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
> Hi Borislav,
> Could you please help to review the patch again since I have
> made changes against the previous version?

I think you're asking me to test that patch, correct?

If so, what is the exact tree I need to apply? tip/x86/apic + those two
patches here? What else? What about the USB chunk which removes the proc
splat, is that somewhere too? Maybe Linus did pull it already?

Please specify what exactly I should test.

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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