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

Jiang Liu
2014-08-06T10:23:01Z

On 2014/8/6 2:37, Borislav Petkov wrote:
> 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.
Hi Borislav,
I have prepared a tree for you at
https://github.com/jiangliu/linux.git suspend2

It's based on tip/master and includes:
1) the patch to fix warning caused by USB controller
2) these two patches to fix failure of suspend/hibernation

Could you please help to check whether suspend/hibernation works as
expect on your platforms?
Thanks!
Gerry

>
> Thanks.
>