PCI: pciehp: add ACPI based slot detection
There is a problem that some non hot-pluggable PCIe slots are detected
as hot-pluggable by pciehp on some platforms. The immediate cause of
this problem is that hot-plug capable bit in the Slot Capabilities
register is set even for non hot-pluggable slots on those platforms.
It seems a BIOS/hardware problem, but we need workaround about that.
Some of those platforms define hot-pluggable PCIe slots on ACPI
namespace properly, while hot-plug capable bit in the Slot
Capabilities register is set improperly. So using ACPI namespace
information in pciehp to detect PCIe hot-pluggable slots would be a
workaround.
This patch adds 'pciehp_detect_mode' module option. When 'acpi' is
specified, pciehp uses ACPI namespace information to detect PCIe
hot-pluggable slots.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index b2801a7..27fd18f 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -220,11 +220,23 @@
#include <acpi/actypes.h>
#include <linux/pci-acpi.h>
+extern void __init pciehp_acpi_slot_detection_init(void);
+extern int pciehp_acpi_slot_detection_check(struct pci_dev *dev);
+
+static inline void pciehp_firmware_init(void)
+{
+ pciehp_acpi_slot_detection_init();
+}
+
static inline int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
+ int retval;
u32 flags = (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |
OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
- return acpi_get_hp_hw_control_from_firmware(dev, flags);
+ retval = acpi_get_hp_hw_control_from_firmware(dev, flags);
+ if (retval)
+ return retval;
+ return pciehp_acpi_slot_detection_check(dev);
}
static inline int pciehp_get_hp_params_from_firmware(struct pci_dev *dev,
@@ -235,6 +247,7 @@
return 0;
}
#else
+#define pciehp_firmware_init() do {} while (0)
#define pciehp_get_hp_hw_control_from_firmware(dev) 0
#define pciehp_get_hp_params_from_firmware(dev, hpp) (-ENODEV)
#endif /* CONFIG_ACPI */