Re: [PATCH 01/11] pci: add pci_bridge_release_unused_res and pci_bus_release_unused_bridge_res

[Yinghai Lu <yinghai@kernel.org>]

On 01/19/2010 01:26 PM, Alex Chiang wrote:
>> +static void __ref pci_bus_release_bridge_resources(struct pci_bus *bus,
>> +						   unsigned long type,
>> +						   enum release_type rel_type)
>> +{
>> +	struct pci_dev *dev;
>> +	bool is_leaf_bridge = true;
>> +
>> +	list_for_each_entry(dev, &bus->devices, bus_list) {
>> +		struct pci_bus *b = dev->subordinate;
>> +		if (!b)
>> +			continue;
>> +
>> +		switch (dev->class >> 8) {
>> +		case PCI_CLASS_BRIDGE_CARDBUS:
>> +			is_leaf_bridge = false;
>> +			break;
>> +
>> +		case PCI_CLASS_BRIDGE_PCI:
>> +		default:
>> +			is_leaf_bridge = false;
>> +			if (rel_type == whole_subtree)
>> +				pci_bus_release_bridge_resources(b, type,
>> +							 whole_subtree);
>> +			break;
>> +		}
>> +	}
> 
> I still don't understand this loop. Can't you write it like this:
> 
> 	list_for_each_entry(dev, &bus->devices, bus_list) {
> 		struct pci_bus *b = dev->subordinate;
> 		if (!b)
> 			continue;
> 
> 		is_leaf_bridge = false;
> 
> 		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)
> 			continue;
> 
> 		if (rel_type == whole_subtree)
> 			pci_bus_release_bridge_resources(b, type,
> 						whole_subtree);
> 	}
> 
> I'm looking at that 'default' label in your switch() statement
> which causes us to always set is_leaf_bridge = false after 'b' is
> valid.

ok