Merge branch 'for-rmk/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable

  * Support for Qualcomm Krait processors (run perf on your phone!)
  * Support for Cortex-A12 (run perf stat on your FPGA!)
  * Support for perf_sample_event_took, allowing us to automatically decrease
    the sample rate if we can't handle the PMU interrupts quickly enough
    (run perf record on your FPGA!).

As part of the Krait support, we also gain support for PPI generation by
the PMU.

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index e2a783fdb98f..7c7a388c85ab 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -730,6 +730,17 @@ static unsigned int get_slot_status(struct acpiphp_slot *slot)
         return (unsigned int)sta;
 }
 
+static inline bool device_status_valid(unsigned int sta)
+{
+        /*
+         * ACPI spec says that _STA may return bit 0 clear with bit 3 set
+         * if the device is valid but does not require a device driver to be
+         * loaded (Section 6.3.7 of ACPI 5.0A).
+         */
+        unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
+        return (sta & mask) == mask;
+}
+
 /**
  * trim_stale_devices - remove PCI devices that are not responding.
  * @dev: PCI device to start walking the hierarchy from.
@@ -745,7 +756,7 @@ static void trim_stale_devices(struct pci_dev *dev)
                 unsigned long long sta;
 
                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
-                alive = (ACPI_SUCCESS(status) && sta == ACPI_STA_ALL)
+                alive = (ACPI_SUCCESS(status) && device_status_valid(sta))
                         || acpiphp_no_hotplug(handle);
         }
         if (!alive) {
@@ -792,7 +803,7 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
                 mutex_lock(&slot->crit_sect);
                 if (slot_no_hotplug(slot)) {
                         ; /* do nothing */
-                } else if (get_slot_status(slot) == ACPI_STA_ALL) {
+                } else if (device_status_valid(get_slot_status(slot))) {
                         /* remove stale devices if any */
                         list_for_each_entry_safe_reverse(dev, tmp,
                                                          &bus->devices, bus_list)