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SubjectRe: [PATCH 2/16 v6] PCI: define PCI resource names in an 'enum'
Bjorn Helgaas wrote:
> On Wednesday 22 October 2008 08:44:24 am Yu Zhao wrote:
>> Bjorn Helgaas wrote:
>>> On Wednesday 22 October 2008 02:40:41 am Yu Zhao wrote:
>>>> This patch moves all definitions of the PCI resource names to an 'enum',
>>>> and also replaces some hard-coded resource variables with symbol
>>>> names. This change eases introduction of device specific resources.
>>> Thanks for removing a bunch of magic numbers from the code.
>>>
>>>> static void
>>>> pci_restore_bars(struct pci_dev *dev)
>>>> {
>>>> - int i, numres;
>>>> -
>>>> - switch (dev->hdr_type) {
>>>> - case PCI_HEADER_TYPE_NORMAL:
>>>> - numres = 6;
>>>> - break;
>>>> - case PCI_HEADER_TYPE_BRIDGE:
>>>> - numres = 2;
>>>> - break;
>>>> - case PCI_HEADER_TYPE_CARDBUS:
>>>> - numres = 1;
>>>> - break;
>>>> - default:
>>>> - /* Should never get here, but just in case... */
>>>> - return;
>>>> - }
>>>> + int i;
>>>>
>>>> - for (i = 0; i < numres; i++)
>>>> + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
>>>> pci_update_resource(dev, i);
>>>> }
>>> The behavior of this function used to depend on dev->hdr_type. Now
>>> we don't look at hdr_type at all, so we do the same thing for all
>>> devices.
>>>
>>> For example, for a CardBus device, we used to call pci_update_resource()
>>> only for BAR 0; now we call it for BARs 0-6.
>>>
>>> Maybe this is safe, but I can't tell from the patch, so I think you
>>> should explain *why* it's safe in the changelog.
>> It's safe because pci_update_resource() will ignore unused resources.
>> E.g., for a Cardbus, only BAR 0 is used and its 'flags' is set, then
>> pci_update_resource() only updates it. BAR 1-6 are ignored since their
>> 'flags' are 0.
>>
>> I'll put more explanation in the changelog.
>
> This is a logically separate change from merely substituting enum
> names for magic numbers, so you might even consider splitting it
> into a separate patch. Better bisection and all that, you know :-)

Will do.

Thanks,
Yu


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