Re: [PATCH part1 v5 5/7] PCI: Add pci_dummy_ops to isolate pci devicetemporarily

From: Yijing Wang
Date: Mon Feb 10 2014 - 03:00:52 EST


Hi Oliver,
Thanks for your review and comments!

>> +static DEFINE_SPINLOCK(pci_freeze_lock);
>
> The lock is used only here.

Also be used in pci_bus_unfreeze_device();

>
>> +/**
>> + * pci_bus_freeze_device - freeze pci bus to access pci device
>> + * @bus: the pci bus to freeze
>> + *
>> + * Replace pci bus ops by pci_dummy_ops, protect system from
>> + * accessing pci devices.
>> + */
>> +void pci_bus_freeze_device(struct pci_bus *bus)
>> +{
>> + struct pci_ops *ops;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&pci_freeze_lock, flags);
>> + ops = pci_bus_set_ops(bus, &pci_dummy_ops);
>> + bus->save_ops = ops;
>> + spin_unlock_irqrestore(&pci_freeze_lock, flags);
>
> Against what exactly are you locking here?

I want to use this spin lock to serialize freeze device and unfreeze device.

Thanks!
Yijing.
>
>
>
>


--
Thanks!
Yijing

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