Merge tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "All of these commits are fixes that have emerged recently and some of
  them fix bugs introduced during this merge window.

  Specifics:

   1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events

      After the recent ACPIPHP changes we've seen some interesting
      breakage on a system that triggers device check notifications
      during boot for non-existing devices.  Although those
      notifications are really spurious, we should be able to deal with
      them nevertheless and that shouldn't introduce too much overhead.
      Four commits to make that work properly.

   2) Memory hotplug and hibernation mutual exclusion rework

      This was maent to be a cleanup, but it happens to fix a classical
      ABBA deadlock between system suspend/hibernation and ACPI memory
      hotplug which is possible if they are started roughly at the same
      time.  Three commits rework memory hotplug so that it doesn't
      acquire pm_mutex and make hibernation use device_hotplug_lock
      which prevents it from racing with memory hotplug.

   3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix

      The ACPI LPSS driver crashes during boot on Apple Macbook Air with
      Haswell that has slightly unusual BIOS configuration in which one
      of the LPSS device's _CRS method doesn't return all of the
      information expected by the driver.  Fix from Mika Westerberg, for
      stable.

   4) ACPICA fix related to Store->ArgX operation

      AML interpreter fix for obscure breakage that causes AML to be
      executed incorrectly on some machines (observed in practice).
      From Bob Moore.

   5) ACPI core fix for PCI ACPI device objects lookup

      There still are cases in which there is more than one ACPI device
      object matching a given PCI device and we don't choose the one
      that the BIOS expects us to choose, so this makes the lookup take
      more criteria into account in those cases.

   6) Fix to prevent cpuidle from crashing in some rare cases

      If the result of cpuidle_get_driver() is NULL, which can happen on
      some systems, cpuidle_driver_ref() will crash trying to use that
      pointer and the Daniel Fu's fix prevents that from happening.

   7) cpufreq fixes related to CPU hotplug

      Stephen Boyd reported a number of concurrency problems with
      cpufreq related to CPU hotplug which are addressed by a series of
      fixes from Srivatsa S Bhat and Viresh Kumar.

   8) cpufreq fix for time conversion in time_in_state attribute

      Time conversion carried out by cpufreq when user space attempts to
      read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state
      won't work correcty if cputime_t doesn't map directly to jiffies.
      Fix from Andreas Schwab.

   9) Revert of a troublesome cpufreq commit

      Commit 7c30ed5 (cpufreq: make sure frequency transitions are
      serialized) was intended to address some known concurrency
      problems in cpufreq related to the ordering of transitions, but
      unfortunately it introduced several problems of its own, so I
      decided to revert it now and address the original problems later
      in a more robust way.

  10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle.

  11) cpufreq fixes related to system suspend/resume

      The recent cpufreq changes that made it preserve CPU sysfs
      attributes over suspend/resume cycles introduced a possible NULL
      pointer dereference that caused it to crash during the second
      attempt to suspend.  Three commits from Srivatsa S Bhat fix that
      problem and a couple of related issues.

  12) cpufreq locking fix

      cpufreq_policy_restore() should acquire the lock for reading, but
      it acquires it for writing.  Fix from Lan Tianyu"

* tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  cpufreq: Acquire the lock in cpufreq_policy_restore() for reading
  cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu
  cpufreq: Restructure if/else block to avoid unintended behavior
  cpufreq: Fix crash in cpufreq-stats during suspend/resume
  intel_pstate: Add Haswell CPU models
  Revert "cpufreq: make sure frequency transitions are serialized"
  cpufreq: Use signed type for 'ret' variable, to store negative error values
  cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes
  cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug
  cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock
  cpufreq: Split __cpufreq_remove_dev() into two parts
  cpufreq: Fix wrong time unit conversion
  cpufreq: serialize calls to __cpufreq_governor()
  cpufreq: don't allow governor limits to be changed when it is disabled
  ACPI / bind: Prefer device objects with _STA to those without it
  ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks
  ACPI / hotplug / PCI: Use _OST to notify firmware about notify status
  ACPI / hotplug / PCI: Avoid doing too much for spurious notifies
  ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field.
  ACPI / hotplug / PCI: Don't trim devices before scanning the namespace
  ...

1 files changed, 47 insertions, 14 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index f6488adf3af1..0b7d23b4ad95 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -487,7 +487,6 @@ static void acpiphp_bus_add(acpi_handle handle)
 {
         struct acpi_device *adev = NULL;
 
-        acpiphp_bus_trim(handle);
         acpi_bus_scan(handle);
         acpi_bus_get_device(handle, &adev);
         if (adev)
@@ -529,6 +528,16 @@ static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
         }
 }
 
+static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
+{
+        struct acpiphp_func *func;
+
+        list_for_each_entry(func, &slot->funcs, sibling)
+                acpiphp_bus_add(func_to_handle(func));
+
+        return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
+}
+
 /**
  * enable_slot - enable, configure a slot
  * @slot: slot to be enabled
@@ -543,12 +552,9 @@ static void __ref enable_slot(struct acpiphp_slot *slot)
         struct acpiphp_func *func;
         int max, pass;
         LIST_HEAD(add_list);
+        int nr_found;
 
-        list_for_each_entry(func, &slot->funcs, sibling)
-                acpiphp_bus_add(func_to_handle(func));
-
-        pci_scan_slot(bus, PCI_DEVFN(slot->device, 0));
-
+        nr_found = acpiphp_rescan_slot(slot);
         max = acpiphp_max_busnr(bus);
         for (pass = 0; pass < 2; pass++) {
                 list_for_each_entry(dev, &bus->devices, bus_list) {
@@ -567,8 +573,11 @@ static void __ref enable_slot(struct acpiphp_slot *slot)
                         }
                 }
         }
-
         __pci_bus_assign_resources(bus, &add_list, NULL);
+        /* Nothing more to do here if there are no new devices on this bus. */
+        if (!nr_found && (slot->flags & SLOT_ENABLED))
+                return;
+
         acpiphp_sanitize_bus(bus);
         acpiphp_set_hpp_values(bus);
         acpiphp_set_acpi_region(slot);
@@ -837,11 +846,22 @@ static void hotplug_event(acpi_handle handle, u32 type, void *data)
         case ACPI_NOTIFY_DEVICE_CHECK:
                 /* device check */
                 dbg("%s: Device check notify on %s\n", __func__, objname);
-                if (bridge)
+                if (bridge) {
                         acpiphp_check_bridge(bridge);
-                else
-                        acpiphp_check_bridge(func->parent);
+                } else {
+                        struct acpiphp_slot *slot = func->slot;
+                        int ret;
 
+                        /*
+                         * Check if anything has changed in the slot and rescan
+                         * from the parent if that's the case.
+                         */
+                        mutex_lock(&slot->crit_sect);
+                        ret = acpiphp_rescan_slot(slot);
+                        mutex_unlock(&slot->crit_sect);
+                        if (ret)
+                                acpiphp_check_bridge(func->parent);
+                }
                 break;
 
         case ACPI_NOTIFY_EJECT_REQUEST:
@@ -867,6 +887,8 @@ static void hotplug_event_work(struct work_struct *work)
         hotplug_event(hp_work->handle, hp_work->type, context);
 
         acpi_scan_lock_release();
+        acpi_evaluate_hotplug_ost(hp_work->handle, hp_work->type,
+                                  ACPI_OST_SC_SUCCESS, NULL);
         kfree(hp_work); /* allocated in handle_hotplug_event() */
         put_bridge(context->func.parent);
 }
@@ -882,11 +904,15 @@ static void hotplug_event_work(struct work_struct *work)
 static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
 {
         struct acpiphp_context *context;
+        u32 ost_code = ACPI_OST_SC_SUCCESS;
 
         switch (type) {
         case ACPI_NOTIFY_BUS_CHECK:
         case ACPI_NOTIFY_DEVICE_CHECK:
+                break;
         case ACPI_NOTIFY_EJECT_REQUEST:
+                ost_code = ACPI_OST_SC_EJECT_IN_PROGRESS;
+                acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
                 break;
 
         case ACPI_NOTIFY_DEVICE_WAKE:
@@ -895,20 +921,21 @@ static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
                 acpi_handle_err(handle, "Device cannot be configured due "
                                 "to a frequency mismatch\n");
-                return;
+                goto out;
 
         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
                 acpi_handle_err(handle, "Device cannot be configured due "
                                 "to a bus mode mismatch\n");
-                return;
+                goto out;
 
         case ACPI_NOTIFY_POWER_FAULT:
                 acpi_handle_err(handle, "Device has suffered a power fault\n");
-                return;
+                goto out;
 
         default:
                 acpi_handle_warn(handle, "Unsupported event type 0x%x\n", type);
-                return;
+                ost_code = ACPI_OST_SC_UNRECOGNIZED_NOTIFY;
+                goto out;
         }
 
         mutex_lock(&acpiphp_context_lock);
@@ -917,8 +944,14 @@ static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
                 get_bridge(context->func.parent);
                 acpiphp_put_context(context);
                 alloc_acpi_hp_work(handle, type, context, hotplug_event_work);
+                mutex_unlock(&acpiphp_context_lock);
+                return;
         }
         mutex_unlock(&acpiphp_context_lock);
+        ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+
+ out:
+        acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 }
 
 /*