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PCI: pciehp: Make pciehp_is_native() stricter

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Previously pciehp_is_native() returned true for any PCI device in a
hierarchy where _OSC says we can use pciehp.  This is incorrect because
bridges without PCI_EXP_SLTCAP_HPC capability should be managed by acpiphp
instead.

Improve pciehp_is_native() to return true only when PCI_EXP_SLTCAP_HPC is
set and the pciehp driver is present.  In any other case return false
to let acpiphp handle those.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: remove NULL pointer check]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Mika Westerberg
2018-05-23 17:24:08 -05:00
committed by Bjorn Helgaas
parent 9310f0dc1c
commit 5352a44a56
4 changed files with 18 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/pci/pci-acpi.c
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@@ -370,26 +370,28 @@ EXPORT_SYMBOL_GPL(pci_get_hp_params);
/**
* pciehp_is_native - Check whether a hotplug port is handled by the OS
* @pdev: Hotplug port to check
* @bridge: Hotplug port to check
*
* Walk up from @pdev to the host bridge, obtain its cached _OSC Control Field
* and return the value of the "PCI Express Native Hot Plug control" bit.
* On failure to obtain the _OSC Control Field return %false.
* Returns true if the given @bridge is handled by the native PCIe hotplug
* driver.
*/
bool pciehp_is_native(struct pci_dev *pdev)
bool pciehp_is_native(struct pci_dev *bridge)
{
struct acpi_pci_root *root;
acpi_handle handle;
const struct pci_host_bridge *host;
u32 slot_cap;
handle = acpi_find_root_bridge_handle(pdev);
if (!handle)
if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
return false;
root = acpi_pci_find_root(handle);
if (!root)
pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
return false;
return root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
if (pcie_ports_native)
return true;
host = pci_find_host_bridge(bridge->bus);
return host->native_pcie_hotplug;
}
/**