ACPI / dock: Initialize ACPI dock subsystem upfront

Commit 3b63aaa70e1 (PCI: acpiphp: Do not use ACPI PCI subdriver
mechanism) introduced an ACPI dock support regression, because it
changed the relative initialization order of the ACPI dock subsystem
and the ACPI-based PCI hotplug (acpiphp).

Namely, the ACPI dock subsystem has to be initialized before
acpiphp_enumerate_slots() is first run, which after commit
3b63aaa70e1 happens during the initial enumeration of the PCI
hierarchy triggered by the initial ACPI namespace scan in
acpi_scan_init().  For this reason, the dock subsystem has to be
initialized before the initial ACPI namespace scan in
acpi_scan_init().

To make that happen, modify the ACPI dock subsystem to be
non-modular and add the invocation of its initialization routine,
acpi_dock_init(), to acpi_scan_init() directly before the initial
namespace scan.

[rjw: Changelog, removal of dock_exit().]
References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov <patrakov@gmail.com>
Tested-by: Illya Klymov <xanf@xanf.me>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 7 insertions, 41 deletions

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index ec117c6c996c..c3b34f94382f 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -994,30 +994,6 @@ err_unregister:
 }
 
 /**
- * dock_remove - free up resources related to the dock station
- */
-static int dock_remove(struct dock_station *ds)
-{
-        struct dock_dependent_device *dd, *tmp;
-        struct platform_device *dock_device = ds->dock_device;
-
-        if (!dock_station_count)
-                return 0;
-
-        /* remove dependent devices */
-        list_for_each_entry_safe(dd, tmp, &ds->dependent_devices, list)
-                kfree(dd);
-
-        list_del(&ds->sibling);
-
-        /* cleanup sysfs */
-        sysfs_remove_group(&dock_device->dev.kobj, &dock_attribute_group);
-        platform_device_unregister(dock_device);
-
-        return 0;
-}
-
-/**
  * find_dock_and_bay - look for dock stations and bays
  * @handle: acpi handle of a device
  * @lvl: unused
@@ -1035,7 +1011,7 @@ find_dock_and_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
         return AE_OK;
 }
 
-static int __init dock_init(void)
+int __init acpi_dock_init(void)
 {
         if (acpi_disabled)
                 return 0;
@@ -1054,19 +1030,3 @@ static int __init dock_init(void)
                 ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
         return 0;
 }
-
-static void __exit dock_exit(void)
-{
-        struct dock_station *tmp, *dock_station;
-
-        unregister_acpi_bus_notifier(&dock_acpi_notifier);
-        list_for_each_entry_safe(dock_station, tmp, &dock_stations, sibling)
-                dock_remove(dock_station);
-}
-
-/*
- * Must be called before drivers of devices in dock, otherwise we can't know
- * which devices are in a dock
- */
-subsys_initcall(dock_init);
-module_exit(dock_exit);
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 297cbf456f86..c610a76d92c4 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -40,6 +40,11 @@ void acpi_container_init(void);
 #else
 static inline void acpi_container_init(void) {}
 #endif
+#ifdef CONFIG_ACPI_DOCK
+void acpi_dock_init(void);
+#else
+static inline void acpi_dock_init(void) {}
+#endif
 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
 void acpi_memory_hotplug_init(void);
 #else
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index b14ac46948c9..27da63061e11 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2042,6 +2042,7 @@ int __init acpi_scan_init(void)
         acpi_lpss_init();
         acpi_container_init();
         acpi_memory_hotplug_init();
+        acpi_dock_init();
 
         mutex_lock(&acpi_scan_lock);
         /*