On 19.01.2016 02:49, liudongdong (C) wrote:
Hi Tomasz, Mark
在 2016/1/18 20:41, Tomasz Nowicki 写道:
On 14.01.2016 16:36, Mark Salter wrote:
+extern struct pci_mcfg_fixup __start_acpi_mcfg_fixups[];
>+extern struct pci_mcfg_fixup __end_acpi_mcfg_fixups[];
>+
>+static struct pci_ops *pci_mcfg_check_quirks(struct acpi_pci_root
*root)
>+{
>+ 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++) {
>+ if ((f->domain == domain || f->domain ==
PCI_MCFG_DOMAIN_ANY) &&
>+ (f->bus_num == bus_num || f->bus_num ==
PCI_MCFG_BUS_ANY) &&
>+ (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.
Tomasz
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