From 683058e315f00a216fd6c79df4f63bc9945ca434 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:16 +0200 Subject: ACPI / hotplug: Use device offline/online for graceful hot-removal Modify the generic ACPI hotplug code to be able to check if devices scheduled for hot-removal may be gracefully removed from the system using the device offline/online mechanism introduced previously. Namely, make acpi_scan_hot_remove() handling device hot-removal call device_offline() for all physical companions of the ACPI device nodes involved in the operation and check the results. If any of the device_offline() calls fails, the function will not progress to the removal phase (which cannot be aborted), unless its (new) force argument is set (in case of a failing offline it will put the devices offlined by it back online). In support of 'forced' device hot-removal, add a new sysfs attribute 'force_remove' that will reside under /sys/firmware/acpi/hotplug/. Signed-off-by: Rafael J. Wysocki Reviewed-by: Toshi Kani --- drivers/acpi/scan.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index fe158fd4f1df..4fd392005ef1 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -27,6 +27,12 @@ extern struct acpi_device *acpi_root; #define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent) +/* + * If set, devices will be hot-removed even if they cannot be put offline + * gracefully (from the kernel's standpoint). + */ +bool acpi_force_hot_remove; + static const char *dummy_hid = "device"; static LIST_HEAD(acpi_device_list); @@ -120,6 +126,59 @@ acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, cha } static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL); +static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl, + void *data, void **ret_p) +{ + struct acpi_device *device = NULL; + struct acpi_device_physical_node *pn; + acpi_status status = AE_OK; + + if (acpi_bus_get_device(handle, &device)) + return AE_OK; + + mutex_lock(&device->physical_node_lock); + + list_for_each_entry(pn, &device->physical_node_list, node) { + int ret; + + ret = device_offline(pn->dev); + if (acpi_force_hot_remove) + continue; + + if (ret < 0) { + status = AE_ERROR; + break; + } + pn->put_online = !ret; + } + + mutex_unlock(&device->physical_node_lock); + + return status; +} + +static acpi_status acpi_bus_online_companions(acpi_handle handle, u32 lvl, + void *data, void **ret_p) +{ + struct acpi_device *device = NULL; + struct acpi_device_physical_node *pn; + + if (acpi_bus_get_device(handle, &device)) + return AE_OK; + + mutex_lock(&device->physical_node_lock); + + list_for_each_entry(pn, &device->physical_node_list, node) + if (pn->put_online) { + device_online(pn->dev); + pn->put_online = false; + } + + mutex_unlock(&device->physical_node_lock); + + return AE_OK; +} + static int acpi_scan_hot_remove(struct acpi_device *device) { acpi_handle handle = device->handle; @@ -136,10 +195,33 @@ static int acpi_scan_hot_remove(struct acpi_device *device) return -EINVAL; } + lock_device_hotplug(); + + status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, + NULL, acpi_bus_offline_companions, NULL, + NULL); + if (ACPI_SUCCESS(status) || acpi_force_hot_remove) + status = acpi_bus_offline_companions(handle, 0, NULL, NULL); + + if (ACPI_FAILURE(status) && !acpi_force_hot_remove) { + acpi_bus_online_companions(handle, 0, NULL, NULL); + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, + acpi_bus_online_companions, NULL, NULL, + NULL); + + unlock_device_hotplug(); + + put_device(&device->dev); + return -EBUSY; + } + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Hot-removing device %s...\n", dev_name(&device->dev))); acpi_bus_trim(device); + + unlock_device_hotplug(); + /* Device node has been unregistered. */ put_device(&device->dev); device = NULL; @@ -236,6 +318,7 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source) int error; mutex_lock(&acpi_scan_lock); + lock_device_hotplug(); acpi_bus_get_device(handle, &device); if (device) { @@ -259,6 +342,7 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source) kobject_uevent(&device->dev.kobj, KOBJ_ONLINE); out: + unlock_device_hotplug(); acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL); mutex_unlock(&acpi_scan_lock); } -- cgit v1.2.3 From ac212b6980d8d5eda705864fc5a8ecddc6d6eacc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:22 +0200 Subject: ACPI / processor: Use common hotplug infrastructure Split the ACPI processor driver into two parts, one that is non-modular, resides in the ACPI core and handles the enumeration and hotplug of processors and one that implements the rest of the existing processor driver functionality. The non-modular part uses an ACPI scan handler object to enumerate processors on the basis of information provided by the ACPI namespace and to hook up with the common ACPI hotplug infrastructure. It also populates the ACPI handle of each processor device having a corresponding object in the ACPI namespace, which allows the driver proper to bind to those devices, and makes the driver bind to them if it is readily available (i.e. loaded) when the scan handler's .attach() routine is running. There are a few reasons to make this change. First, switching the ACPI processor driver to using the common ACPI hotplug infrastructure reduces code duplication and size considerably, even though a new file is created along with a header comment etc. Second, since the common hotplug code attempts to offline devices before starting the (non-reversible) removal procedure, it will abort (and possibly roll back) hot-remove operations involving processors if cpu_down() returns an error code for one of them instead of continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove is unset). That is a more desirable behavior than what the current code does. Finally, the separation of the scan/hotplug part from the driver proper makes it possible to simplify the driver's .remove() routine, because it doesn't need to worry about the possible cleanup related to processor removal any more (the scan/hotplug part is responsible for that now) and can handle device removal and driver removal symmetricaly (i.e. as appropriate). Some user-visible changes in sysfs are made (for example, the 'sysdev' link from the ACPI device node to the processor device's directory is gone and a 'physical_node' link is present instead and a corresponding 'firmware_node' is present in the processor device's directory, the processor driver is now visible under /sys/bus/cpu/drivers/ and bound to the processor device), but that shouldn't affect the functionality that users care about (frequency scaling, C-states and thermal management). Tested on my venerable Toshiba Portege R500. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/acpi/scan.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 4fd392005ef1..ad82bb2a37e0 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2124,6 +2124,7 @@ int __init acpi_scan_init(void) acpi_pci_root_init(); acpi_pci_link_init(); + acpi_processor_init(); acpi_platform_init(); acpi_lpss_init(); acpi_csrt_init(); -- cgit v1.2.3 From 2e199192df85eb936a7829dc28b57b85c59c86fc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 May 2013 10:40:35 +0200 Subject: ACPI: Drop removal_type field from struct acpi_device The ACPI processor driver was the only user of the removal_type field in struct acpi_device, but it doesn't use that field any more after recent changes. Thus, removal_type has no more users, so drop it along with the associated data type. Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani --- drivers/acpi/scan.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index ad82bb2a37e0..ba8ee6cbf0f1 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1036,7 +1036,6 @@ int acpi_device_add(struct acpi_device *device, printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n", dev_name(&device->dev)); - device->removal_type = ACPI_BUS_REMOVAL_NORMAL; return 0; err: @@ -2025,7 +2024,6 @@ static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used, if (!acpi_bus_get_device(handle, &device)) { struct acpi_scan_handler *dev_handler = device->handler; - device->removal_type = ACPI_BUS_REMOVAL_EJECT; if (dev_handler) { if (dev_handler->detach) dev_handler->detach(device); -- cgit v1.2.3 From 303bfdb1a14d0460feb859cd008ff81da36b517c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 May 2013 10:43:13 +0200 Subject: ACPI / scan: Add second pass of companion offlining to hot-remove code As indicated by comments in mm/memory_hotplug.c:remove_memory(), if CONFIG_MEMCG is set, it may not be possible to offline all of the memory blocks held by one module (FRU) in one pass (because one of them may be used by the others to store page cgroup in that case and that block has to be offlined before the other ones). To handle that arguably corner case, add a second pass of companion device offlining to acpi_scan_hot_remove() and make it ignore errors returned in the first pass (and make it skip the second pass if the first one is successful). Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani --- drivers/acpi/scan.c | 71 +++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 19 deletions(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index ba8ee6cbf0f1..2959fe1ce43e 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -131,6 +131,7 @@ static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl, { struct acpi_device *device = NULL; struct acpi_device_physical_node *pn; + bool second_pass = (bool)data; acpi_status status = AE_OK; if (acpi_bus_get_device(handle, &device)) @@ -141,15 +142,26 @@ static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl, list_for_each_entry(pn, &device->physical_node_list, node) { int ret; + if (second_pass) { + /* Skip devices offlined by the first pass. */ + if (pn->put_online) + continue; + } else { + pn->put_online = false; + } ret = device_offline(pn->dev); if (acpi_force_hot_remove) continue; - if (ret < 0) { - status = AE_ERROR; - break; + if (ret >= 0) { + pn->put_online = !ret; + } else { + *ret_p = pn->dev; + if (second_pass) { + status = AE_ERROR; + break; + } } - pn->put_online = !ret; } mutex_unlock(&device->physical_node_lock); @@ -185,6 +197,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device) acpi_handle not_used; struct acpi_object_list arg_list; union acpi_object arg; + struct device *errdev; acpi_status status; unsigned long long sta; @@ -197,22 +210,42 @@ static int acpi_scan_hot_remove(struct acpi_device *device) lock_device_hotplug(); - status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, - NULL, acpi_bus_offline_companions, NULL, - NULL); - if (ACPI_SUCCESS(status) || acpi_force_hot_remove) - status = acpi_bus_offline_companions(handle, 0, NULL, NULL); - - if (ACPI_FAILURE(status) && !acpi_force_hot_remove) { - acpi_bus_online_companions(handle, 0, NULL, NULL); + /* + * Carry out two passes here and ignore errors in the first pass, + * because if the devices in question are memory blocks and + * CONFIG_MEMCG is set, one of the blocks may hold data structures + * that the other blocks depend on, but it is not known in advance which + * block holds them. + * + * If the first pass is successful, the second one isn't needed, though. + */ + errdev = NULL; + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, + NULL, acpi_bus_offline_companions, + (void *)false, (void **)&errdev); + acpi_bus_offline_companions(handle, 0, (void *)false, (void **)&errdev); + if (errdev) { + errdev = NULL; acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, - acpi_bus_online_companions, NULL, NULL, - NULL); - - unlock_device_hotplug(); - - put_device(&device->dev); - return -EBUSY; + NULL, acpi_bus_offline_companions, + (void *)true , (void **)&errdev); + if (!errdev || acpi_force_hot_remove) + acpi_bus_offline_companions(handle, 0, (void *)true, + (void **)&errdev); + + if (errdev && !acpi_force_hot_remove) { + dev_warn(errdev, "Offline failed.\n"); + acpi_bus_online_companions(handle, 0, NULL, NULL); + acpi_walk_namespace(ACPI_TYPE_ANY, handle, + ACPI_UINT32_MAX, + acpi_bus_online_companions, NULL, + NULL, NULL); + + unlock_device_hotplug(); + + put_device(&device->dev); + return -EBUSY; + } } ACPI_DEBUG_PRINT((ACPI_DB_INFO, -- cgit v1.2.3 From d9e455f53f6fb93c764de2399c3894bbdfd2caa7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 10 Jun 2013 13:00:50 +0200 Subject: ACPI / scan: Simplify ACPI driver probing There is no particular reason why acpi_bus_driver_init() needs to be a separate function and its location with respect to its only caller, acpi_device_probe(), makes the code a bit difficult to follow. Besides, it doesn't really make sense to check if 'device' is not NULL in acpi_bus_driver_init(), because we've already dereferenced dev->driver in acpi_device_probe() at that point and, moreover, 'device' cannot be NULL then, because acpi_device_probe() is called via really_probe() (which also sets dev->driver for that matter). For these reasons, drop acpi_bus_driver_init() altogether and move the remaining code from it directly into acpi_device_probe(). Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 81 ++++++++++++++++++----------------------------------- 1 file changed, 27 insertions(+), 54 deletions(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index b14ac46948c9..4eeea2262454 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -816,32 +816,40 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device) acpi_device_notify); } -static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *); -static int acpi_device_probe(struct device * dev) +static int acpi_device_probe(struct device *dev) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver); int ret; - ret = acpi_bus_driver_init(acpi_dev, acpi_drv); - if (!ret) { - if (acpi_drv->ops.notify) { - ret = acpi_device_install_notify_handler(acpi_dev); - if (ret) { - if (acpi_drv->ops.remove) - acpi_drv->ops.remove(acpi_dev); - acpi_dev->driver = NULL; - acpi_dev->driver_data = NULL; - return ret; - } - } + if (!acpi_drv->ops.add) + return -ENOSYS; - ACPI_DEBUG_PRINT((ACPI_DB_INFO, - "Found driver [%s] for device [%s]\n", - acpi_drv->name, acpi_dev->pnp.bus_id)); - get_device(dev); + ret = acpi_drv->ops.add(acpi_dev); + if (ret) + return ret; + + acpi_dev->driver = acpi_drv; + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Driver [%s] successfully bound to device [%s]\n", + acpi_drv->name, acpi_dev->pnp.bus_id)); + + if (acpi_drv->ops.notify) { + ret = acpi_device_install_notify_handler(acpi_dev); + if (ret) { + if (acpi_drv->ops.remove) + acpi_drv->ops.remove(acpi_dev); + + acpi_dev->driver = NULL; + acpi_dev->driver_data = NULL; + return ret; + } } - return ret; + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n", + acpi_drv->name, acpi_dev->pnp.bus_id)); + get_device(dev); + return 0; } static int acpi_device_remove(struct device * dev) @@ -997,41 +1005,6 @@ static void acpi_device_unregister(struct acpi_device *device) /* -------------------------------------------------------------------------- Driver Management -------------------------------------------------------------------------- */ -/** - * acpi_bus_driver_init - add a device to a driver - * @device: the device to add and initialize - * @driver: driver for the device - * - * Used to initialize a device via its device driver. Called whenever a - * driver is bound to a device. Invokes the driver's add() ops. - */ -static int -acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver) -{ - int result = 0; - - if (!device || !driver) - return -EINVAL; - - if (!driver->ops.add) - return -ENOSYS; - - result = driver->ops.add(device); - if (result) - return result; - - device->driver = driver; - - /* - * TBD - Configuration Management: Assign resources to device based - * upon possible configuration and currently allocated resources. - */ - - ACPI_DEBUG_PRINT((ACPI_DB_INFO, - "Driver successfully bound to device\n")); - return 0; -} - /** * acpi_bus_register_driver - register a driver with the ACPI bus * @driver: driver being registered -- cgit v1.2.3 From 24071f472d813fccacc1ef7356b1f41422a1b968 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 16 Jun 2013 00:36:41 +0200 Subject: ACPI / scan: Do not bind ACPI drivers to objects with scan handlers ACPI drivers must not be bound to device objects having scan handlers attatched to them, so make acpi_device_probe() fail with -EINVAL if the device object being probed has an ACPI scan handler. After this change the analogous check introduced into the ACPI video driver by commit 8c9b7a7 (ACPI / video: Do not bind to device objects with a scan handler) is not necessary any more and may be dropped, so drop it. Signed-off-by: Rafael J. Wysocki Tested-by: Tony Luck Acked-by: Toshi Kani --- drivers/acpi/scan.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 4eeea2262454..54529424a0a5 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -822,6 +822,9 @@ static int acpi_device_probe(struct device *dev) struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver); int ret; + if (acpi_dev->handler) + return -EINVAL; + if (!acpi_drv->ops.add) return -ENOSYS; -- cgit v1.2.3 From 2fa97feb4406c546b52e35b6b6c50cb8f63425d2 Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Wed, 5 Jun 2013 02:27:50 +0000 Subject: ACPI: Add CMOS RTC Operation Region handler support On HP Folio 13-2000, the BIOS defines a CMOS RTC Operation Region and the EC's _REG methord accesses that region. Thus an appropriate address space handler must be registered for that region before the EC driver is loaded. Introduce a mechanism for adding CMOS RTC address space handlers. Register an ACPI scan handler for CMOS RTC devices such that, when a device of that kind is detected during an ACPI namespace scan, a common CMOS RTC operation region address space handler will be installed for it. References: https://bugzilla.kernel.org/show_bug.cgi?id=54621 Reported-and-tested-by: Stefan Nagy Signed-off-by: Lan Tianyu Cc: 3.9+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index b14ac46948c9..a514be216440 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2040,6 +2040,7 @@ int __init acpi_scan_init(void) acpi_pci_link_init(); acpi_platform_init(); acpi_lpss_init(); + acpi_cmos_rtc_init(); acpi_container_init(); acpi_memory_hotplug_init(); -- cgit v1.2.3 From b67cf7c44c7e6b485f1c255ac3c1fe98cc99b677 Mon Sep 17 00:00:00 2001 From: Haicheng Li Date: Thu, 4 Jul 2013 12:07:11 +0800 Subject: ACPI / scan: remove unused LIST_HEAD(acpi_device_list) The acpi_device_list list is not used, so removed it. [rjw: Changelog] Signed-off-by: Haicheng Li Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index dfe76f17cfc4..10985573aaa7 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -35,7 +35,6 @@ bool acpi_force_hot_remove; static const char *dummy_hid = "device"; -static LIST_HEAD(acpi_device_list); static LIST_HEAD(acpi_bus_id_list); static DEFINE_MUTEX(acpi_scan_lock); static LIST_HEAD(acpi_scan_handlers_list); -- cgit v1.2.3 From 3a391a39593b48341f0908511590a6c0e55cc069 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 12 Jul 2013 13:45:59 +0200 Subject: ACPI / scan: Do not try to attach scan handlers to devices having them In acpi_bus_device_attach(), if there is an ACPI device object for the given handle and that device object has a scan handler attached to it already, there's nothing more to do for that handle. Moreover, if acpi_scan_attach_handler() is called then, it may execute the .attach() callback of the ACPI scan handler already attached to the device object and that may lead to interesting breakage. For this reason, make acpi_bus_device_attach() return success immediately when the handle's device object has a scan handler attached to it. Reported-by: Toshi Kani Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani Cc: 3.10+ --- drivers/acpi/scan.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 10985573aaa7..080d75962c57 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1981,6 +1981,9 @@ static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used, if (acpi_bus_get_device(handle, &device)) return AE_CTRL_DEPTH; + if (device->handler) + return AE_OK; + ret = acpi_scan_attach_handler(device); if (ret) return ret > 0 ? AE_OK : AE_CTRL_DEPTH; -- cgit v1.2.3 From 8832f7e43fa7f0f19bd54e13766a825dd1ed4d6f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 8 Jul 2013 02:01:53 +0200 Subject: ACPI / scan: Always call acpi_bus_scan() for bus check notifications An ACPI_NOTIFY_BUS_CHECK notification means that we should scan the entire namespace starting from the given handle even if the device represented by that handle is present (other devices below it may just have appeared). For this reason, modify acpi_scan_bus_device_check() to always run acpi_bus_scan() if the notification being handled is of type ACPI_NOTIFY_BUS_CHECK. Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani Cc: 3.10+ --- drivers/acpi/scan.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 080d75962c57..8a46c924effd 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -352,10 +352,12 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source) mutex_lock(&acpi_scan_lock); lock_device_hotplug(); - acpi_bus_get_device(handle, &device); - if (device) { - dev_warn(&device->dev, "Attempt to re-insert\n"); - goto out; + if (ost_source != ACPI_NOTIFY_BUS_CHECK) { + acpi_bus_get_device(handle, &device); + if (device) { + dev_warn(&device->dev, "Attempt to re-insert\n"); + goto out; + } } acpi_evaluate_hotplug_ost(handle, ost_source, ACPI_OST_SC_INSERT_IN_PROGRESS, NULL); -- cgit v1.2.3