-------- Original Message --------
Subject: Re: [PATCH 2/5]PCI: x86 MMCONFIG: add legacy pci conf functions
Date: Wed, 19 Dec 2007 19:07:27 -0500
From: Tony Camuso <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: Greg KH <[EMAIL PROTECTED]>
References:
<[EMAIL PROTECTED]>
<[EMAIL PROTECTED]>
<[EMAIL PROTECTED]>
Greg KH wrote:
+struct pci_ops pci_legacy_ops = {
+ .read = pci_ops_legacy_read,
+ .write = pci_ops_legacy_write,
+};
This whole structure is never used in this patch, why add it now?
It gets used by the routine pcibios_fix_bus_scan_quirk in
arch/x86/pci/common.c
/*
* Before we decide to use direct hardware access mechanisms, we try to do some
@@ -258,18 +284,28 @@ void __init pci_direct_init(int type)
{
if (type == 0)
return;
- printk(KERN_INFO "PCI: Using configuration type %d\n", type);
- if (type == 1)
+ if (type == 1) {
raw_pci_ops = &pci_direct_conf1;
- else
+ pci_legacy_conf = &pci_direct_conf1;
+ } else {
raw_pci_ops = &pci_direct_conf2;
+ pci_legacy_conf = &pci_direct_conf2;
Why have two pointers to the same thing? What is pci_legacy_conf going
to be used for? Why not just use raw_pci_ops?
thanks,
greg k-h
The way the code works today, when raw_pci_ops is set to use mmconf,
it is platform-wide. Legacy pci config reads are not available.
I would have simply used the pci_direct_conf1, but because there can
also be a pci_direct_conf2, I thought it best to abstract it as
pci_legacy_conf.
A pointer to struct pci_ops pci_legacy_ops data is written into the
pci_bus.ops field for buses that must use legacy pci config access.
The other busses can continue to use the pointer to the mmconf pci_ops.
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