? 2016/1/19 15:55, Tomasz Nowicki ??:

On 19.01.2016 02:49, liudongdong (C) wrote:

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Hi Tomasz, Mark

? 2016/1/18 20:41, Tomasz Nowicki ??:

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On 14.01.2016 16:36, Mark Salter wrote:

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+extern struct pci_mcfg_fixup __start_acpi_mcfg_fixups[];

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+extern struct pci_mcfg_fixup __end_acpi_mcfg_fixups[];
+
+static struct pci_ops *pci_mcfg_check_quirks(struct acpi_pci_root

*root)

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+{
+    struct pci_mcfg_fixup *f;
+    int bus_num = root->secondary.start;
+    int domain = root->segment;
+
+    /*
+     * First match against PCI topology <domain:bus> then use DMI or
+     * custom match handler.
+     */
+    for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups;

f++) {

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+        if ((f->domain == domain || f->domain ==

PCI_MCFG_DOMAIN_ANY) &&

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+            (f->bus_num == bus_num || f->bus_num ==

PCI_MCFG_BUS_ANY) &&

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+            (f->system ? dmi_check_system(f->system) : 0 ||
+             f->match ? f->match(f, root) : 0))
+            return f->ops;

I think this would be better as:

            (f->system ? dmi_check_system(f->system) : 1 &&
             f->match ? f->match(f, root) : 1))
            return f->ops;

Otherwise, one has to call dmi_check_system() from f->match() if
access to root is needed.

Non-DMI, we need not to call dmi_check_system() from f->match(),
we can use _HID to decide to hook the pci_ops or not.

Sorry, but I dont understand your point. Can you elaborate?

With Mark modification, you can use the following cases to identify platform:
1. DMI only
2. f->match() only (_HID can be used there)
3. DMI and f->match()

DMI used to be very convenient way to recognise platform, sometimes it is not enough, hence f->match() alternative.

Yes, you are right,  I was wrong.
In my case, I can use the second point.
2. f->match() only (_HID can be used there)

Thanks
Dongdong

Tomasz



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