[PATCH v2] PCI: Apply _HPX link control for all supported pcie device

[Yinghai Lu <yinghai@kernel.org>]

With commit 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration")
and following commits, we apply _HPX for pci devices.

that is called via pci_scan_slot
			==>pci_scan_single_device
				==>pci_device_add
					==>pci_configure_device
						==>program_hpp_type2
and dev->subordinate is not allocated yet.

So that link control setup get skipped.

Acoording to ACPI spec, there is no requirement that need to be set to pcie
root port or downstream port.

We could just change to pcie_cap_has_lnkctl to cover all pcie devices with
link control cap.

-v2: Do not move pcie_cap_has_lnkctl() out of pci/access.c according to Bjorn.

Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/pci/access.c |    2 +-
 drivers/pci/pci.h    |    2 ++
 drivers/pci/probe.c  |    2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/pci/probe.c
===================================================================
--- linux-2.6.orig/drivers/pci/probe.c
+++ linux-2.6/drivers/pci/probe.c
@@ -1323,7 +1323,7 @@ static void program_hpp_type2(struct pci
 			~hpp->pci_exp_devctl_and, hpp->pci_exp_devctl_or);
 
 	/* Initialize Link Control Register */
-	if (dev->subordinate)
+	if (pcie_cap_has_lnkctl(dev))
 		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
 			~hpp->pci_exp_lnkctl_and, hpp->pci_exp_lnkctl_or);
 
Index: linux-2.6/drivers/pci/pci.h
===================================================================
--- linux-2.6.orig/drivers/pci/pci.h
+++ linux-2.6/drivers/pci/pci.h
@@ -6,6 +6,8 @@
 
 extern const unsigned char pcie_link_speed[];
 
+bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
+
 /* Functions internal to the PCI core code */
 
 int pci_create_sysfs_dev_files(struct pci_dev *pdev);
Index: linux-2.6/drivers/pci/access.c
===================================================================
--- linux-2.6.orig/drivers/pci/access.c
+++ linux-2.6/drivers/pci/access.c
@@ -444,7 +444,7 @@ static inline int pcie_cap_version(const
 	return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS;
 }
 
-static inline bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
+bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
 {
 	int type = pci_pcie_type(dev);