[PATCH v16 0/5] shut down devices asynchronously

[PATCH v16 0/5] shut down devices asynchronously

[David Jeffery]

These patches are now rebased against the driver-core tree's driver-core-next
branch. Please let me know if there is a different tree/branch which would be
better to use for possible inclusion of these patches.

This patchset allows the kernel to shutdown devices asynchronously and
unrelated async devices to be shut down in parallel to each other.

Only devices which explicitly enable it are shut down asynchronously. The
default is for a device to be shut down from the synchronous shutdown loop.

This can dramatically reduce system shutdown/reboot time on systems that
have multiple devices that take many seconds to shut down (like certain
NVMe drives). On one system tested, the shutdown time went from 11 minutes
without this patch to 55 seconds with the patch. And on another system from
80 seconds to 11.

And thank you to everyone who has spent some of their valuable time
providing reviews, suggestions, criticisms, or tests on the various
iterations of this patchset.

Changes from V15:

The async_shutdown bit field is converted to a device flags bit
Convert all patches to use the flag bit accessor macros to set or check if
  async shutdown should be used
Added documentation on the kernel parameter to control use of async shutdown

Changes from V14:

Remove unneeded use of '!!' with boolean type

Changes from V13:

Remove duplicate flagging of async shutdown on scsi hosts/targets/devices

Changes from V12:

Only acquire a parent reference if acquiring the parent's lock
device_enable_async_shutdown should return void
Minor comment and description cleanups

Changes from V11:

  * Swap the order of the first two patches
  * Rework conditional parent locking so that lock and unlock no longer use
    separate conditional checks
  * Remove an used variable
  * Comment and description text cleanups

Changes from V10:

Reworked to more closely match the design used for async suspend
  * No longer uses async subsystem cookies for synchronization
  * Minimized changes to struct device
  * Enable async shutdown for pci and scsi devices which support async suspend

Changes from V9:

Address resource and timing issues when spawning a unique async thread
for every device during shutdown:
  * Make the asynchronous threads able to shut down multiple devices,
    instead of spawning a unique thread for every device.
  * Modify core kernel async code with a custom wake function so it
    doesn't wake up a thread waiting to synchronize on a cookie until
    the cookie has reached the desired value, instead of waking up
    every waiting thread to check the cookie every time an async thread
    ends.

Changes from V8:

Deal with shutdown hangs resulting when a parent/supplier device is
  later in the devices_kset list than its children/consumers:
  * Ignore sync_state_only devlinks for shutdown dependencies
  * Ignore shutdown_after for devices that don't want async shutdown
  * Add a sanity check to revert to sync shutdown for any device that
    would otherwise wait for a child/consumer shutdown that hasn't
    already been scheduled

Changes from V7:

Do not expose driver async_shutdown_enable in sysfs.
Wrapped a long line.

Changes from V6:

Removed a sysfs attribute that allowed the async device shutdown to be
"on" (with driver opt-out), "safe" (driver opt-in), or "off"... what was
previously "safe" is now the only behavior, so drivers now only need to
have the option to enable or disable async shutdown.

Changes from V5:

Separated into multiple patches to make review easier.
Reworked some code to make it more readable
Made devices wait for consumers to shut down, not just children
  (suggested by David Jeffery)

Changes from V4:

Change code to use cookies for synchronization rather than async domains
Allow async shutdown to be disabled via sysfs, and allow driver opt-in or
  opt-out of async shutdown (when not disabled), with ability to control
  driver opt-in/opt-out via sysfs
  
Changes from V3:

Bug fix (used "parent" not "dev->parent" in device_shutdown)
 
Changes from V2:
 
Removed recursive functions to schedule children to be shutdown before
  parents, since existing device_shutdown loop will already do this
 
Changes from V1:

Rewritten using kernel async code (suggested by Lukas Wunner)


Stuart Hayes (2):
  driver core: separate function to shutdown one device
  driver core: do not always lock parent in shutdown

David Jeffery (3):
  driver core: async device shutdown infrastructure
  PCI: Enable async shutdown support
  scsi: Enable async shutdown support

 .../admin-guide/kernel-parameters.txt         |  10 +
 drivers/base/base.h                           |   2 +
 drivers/base/core.c                           | 180 ++++++++++++++----
 drivers/pci/probe.c                           |   2 +
 drivers/scsi/hosts.c                          |   2 +
 drivers/scsi/scsi_sysfs.c                     |   3 +
 include/linux/device.h                        |   2 +
 7 files changed, 165 insertions(+), 36 deletions(-)

-- 
2.53.0

[PATCH 1/5] driver core: separate function to shutdown one device

[David Jeffery]

Make a separate function for the part of device_shutdown() that does the
shutown for a single device.  This is in preparation for making device
shutdown asynchronous.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Tarun Sahu <tarunsahu@google.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 drivers/base/core.c | 71 +++++++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 32 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d49420e066de..127432248165 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4795,12 +4795,48 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
 	return error;
 }
 
+static void shutdown_one_device(struct device *dev)
+{
+	struct device *parent = dev->parent;
+
+	/* hold lock to avoid race with probe/release */
+	if (parent)
+		device_lock(parent);
+	device_lock(dev);
+
+	/* Don't allow any more runtime suspends */
+	pm_runtime_get_noresume(dev);
+	pm_runtime_barrier(dev);
+
+	if (dev->class && dev->class->shutdown_pre) {
+		if (initcall_debug)
+			dev_info(dev, "shutdown_pre\n");
+		dev->class->shutdown_pre(dev);
+	}
+	if (dev->bus && dev->bus->shutdown) {
+		if (initcall_debug)
+			dev_info(dev, "shutdown\n");
+		dev->bus->shutdown(dev);
+	} else if (dev->driver && dev->driver->shutdown) {
+		if (initcall_debug)
+			dev_info(dev, "shutdown\n");
+		dev->driver->shutdown(dev);
+	}
+
+	device_unlock(dev);
+	if (parent)
+		device_unlock(parent);
+
+	put_device(parent);
+	put_device(dev);
+}
+
 /**
  * device_shutdown - call ->shutdown() on each device to shutdown.
  */
 void device_shutdown(void)
 {
-	struct device *dev, *parent;
+	struct device *dev;
 
 	wait_for_device_probe();
 	device_block_probing();
@@ -4822,7 +4858,7 @@ void device_shutdown(void)
 		 * prevent it from being freed because parent's
 		 * lock is to be held
 		 */
-		parent = get_device(dev->parent);
+		get_device(dev->parent);
 		get_device(dev);
 		/*
 		 * Make sure the device is off the kset list, in the
@@ -4831,36 +4867,7 @@ void device_shutdown(void)
 		list_del_init(&dev->kobj.entry);
 		spin_unlock(&devices_kset->list_lock);
 
-		/* hold lock to avoid race with probe/release */
-		if (parent)
-			device_lock(parent);
-		device_lock(dev);
-
-		/* Don't allow any more runtime suspends */
-		pm_runtime_get_noresume(dev);
-		pm_runtime_barrier(dev);
-
-		if (dev->class && dev->class->shutdown_pre) {
-			if (initcall_debug)
-				dev_info(dev, "shutdown_pre\n");
-			dev->class->shutdown_pre(dev);
-		}
-		if (dev->bus && dev->bus->shutdown) {
-			if (initcall_debug)
-				dev_info(dev, "shutdown\n");
-			dev->bus->shutdown(dev);
-		} else if (dev->driver && dev->driver->shutdown) {
-			if (initcall_debug)
-				dev_info(dev, "shutdown\n");
-			dev->driver->shutdown(dev);
-		}
-
-		device_unlock(dev);
-		if (parent)
-			device_unlock(parent);
-
-		put_device(dev);
-		put_device(parent);
+		shutdown_one_device(dev);
 
 		spin_lock(&devices_kset->list_lock);
 	}
-- 
2.53.0

[PATCH 2/5] driver core: do not always lock parent in shutdown

[David Jeffery]

Don't lock a parent device unless it is needed in device_shutdown. This
is in preparation for making device shutdown asynchronous, when it will
be needed to allow children of a common parent to shut down
simultaneously.

And only acquire a reference to the parent device if the parent is to be
locked.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Tarun Sahu <tarunsahu@google.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 drivers/base/core.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 127432248165..6e2c37115bc1 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4795,13 +4795,8 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
 	return error;
 }
 
-static void shutdown_one_device(struct device *dev)
+static void __shutdown_one_device(struct device *dev)
 {
-	struct device *parent = dev->parent;
-
-	/* hold lock to avoid race with probe/release */
-	if (parent)
-		device_lock(parent);
 	device_lock(dev);
 
 	/* Don't allow any more runtime suspends */
@@ -4824,10 +4819,23 @@ static void shutdown_one_device(struct device *dev)
 	}
 
 	device_unlock(dev);
-	if (parent)
+}
+
+static void shutdown_one_device(struct device *dev)
+{
+	struct device *parent;
+
+	/* hold lock if needed to avoid race with probe/release */
+	if (dev->bus && dev->bus->need_parent_lock &&
+	    (parent = get_device(dev->parent))) {
+		device_lock(parent);
+		__shutdown_one_device(dev);
 		device_unlock(parent);
+		put_device(parent);
+	} else {
+		__shutdown_one_device(dev);
+	}
 
-	put_device(parent);
 	put_device(dev);
 }
 
@@ -4853,12 +4861,6 @@ void device_shutdown(void)
 		dev = list_entry(devices_kset->list.prev, struct device,
 				kobj.entry);
 
-		/*
-		 * hold reference count of device's parent to
-		 * prevent it from being freed because parent's
-		 * lock is to be held
-		 */
-		get_device(dev->parent);
 		get_device(dev);
 		/*
 		 * Make sure the device is off the kset list, in the
-- 
2.53.0

[PATCH 3/5] driver core: async device shutdown infrastructure

[David Jeffery]

Patterned after async suspend, allow devices to mark themselves as wanting
to perform async shutdown. Devices using async shutdown wait only for their
dependencies to shutdown before executing their shutdown routine.

Sync shutdown devices are shut down one at a time and will only wait for an
async shutdown device if the async device is a dependency.

Enabled by default, async shutdown can be explicitly enabled or disabled
by using the kernel parameter "core.async_shutdown=<bool>"

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Tarun Sahu <tarunsahu@google.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 .../admin-guide/kernel-parameters.txt         |  10 ++
 drivers/base/base.h                           |   2 +
 drivers/base/core.c                           | 101 +++++++++++++++++-
 include/linux/device.h                        |   2 +
 4 files changed, 114 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b5a51a36a048..dd912f47ace4 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1019,6 +1019,16 @@ Kernel parameters
 			seconds. A value of 0 disables the blank timer.
 			Defaults to 0.
 
+	core.async_shutdown=
+			[KNL]
+			Format: <bool>
+			Enable or disable asynchronous shutdown support. When
+			enabled, on system shutdown unrelated devices flagged
+			as async shutdown compatible may be shut down in
+			parallel and asynchronously. When disabled, device
+			shutdown is performed in a serially and synchronously.
+			Enabled by default.
+
 	coredump_filter=
 			[KNL] Change the default value for
 			/proc/<pid>/coredump_filter.
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 483b99b4fa3d..aefa4f256d59 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -103,6 +103,7 @@ struct driver_private {
  *			   dev_err_probe() for later retrieval via debugfs
  * @device: pointer back to the struct device that this structure is
  *	    associated with.
+ * @complete: completion for device shutdown ordering
  * @dead: This device is currently either in the process of or has been
  *	  removed from the system. Any asynchronous events scheduled for this
  *	  device should exit without taking any action.
@@ -119,6 +120,7 @@ struct device_private {
 	const struct device_driver *async_driver;
 	char *deferred_probe_reason;
 	struct device *device;
+	struct completion complete;
 	u8 dead:1;
 };
 #define to_device_private_parent(obj)	\
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6e2c37115bc1..cab10b0e70db 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/async.h>
 #include <linux/blkdev.h>
 #include <linux/cleanup.h>
 #include <linux/cpufreq.h>
@@ -37,6 +38,10 @@
 #include "physical_location.h"
 #include "power/power.h"
 
+static bool async_shutdown = true;
+module_param(async_shutdown, bool, 0644);
+MODULE_PARM_DESC(async_shutdown, "Enable asynchronous device shutdown support");
+
 /* Device links support. */
 static LIST_HEAD(deferred_sync);
 static unsigned int defer_sync_state_count = 1;
@@ -3536,6 +3541,7 @@ static int device_private_init(struct device *dev)
 	klist_init(&dev->p->klist_children, klist_children_get,
 		   klist_children_put);
 	INIT_LIST_HEAD(&dev->p->deferred_probe);
+	init_completion(&dev->p->complete);
 	return 0;
 }
 
@@ -4795,6 +4801,37 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
 	return error;
 }
 
+static bool wants_async_shutdown(struct device *dev)
+{
+	return async_shutdown && dev_async_shutdown(dev);
+}
+
+static int wait_for_device_shutdown(struct device *dev, void *data)
+{
+	bool async = *(bool *)data;
+
+	if (async || wants_async_shutdown(dev))
+		wait_for_completion(&dev->p->complete);
+
+	return 0;
+}
+
+static void wait_for_shutdown_dependencies(struct device *dev, bool async)
+{
+	struct device_link *link;
+	int idx;
+
+	device_for_each_child(dev, &async, wait_for_device_shutdown);
+
+	idx = device_links_read_lock();
+
+	dev_for_each_link_to_consumer(link, dev)
+		if (!device_link_flag_is_sync_state_only(link->flags))
+			wait_for_device_shutdown(link->consumer, &async);
+
+	device_links_read_unlock(idx);
+}
+
 static void __shutdown_one_device(struct device *dev)
 {
 	device_lock(dev);
@@ -4818,6 +4855,8 @@ static void __shutdown_one_device(struct device *dev)
 		dev->driver->shutdown(dev);
 	}
 
+	complete_all(&dev->p->complete);
+
 	device_unlock(dev);
 }
 
@@ -4839,6 +4878,55 @@ static void shutdown_one_device(struct device *dev)
 	put_device(dev);
 }
 
+static void async_shutdown_handler(void *data, async_cookie_t cookie)
+{
+	struct device *dev = data;
+
+	wait_for_shutdown_dependencies(dev, true);
+	shutdown_one_device(dev);
+}
+
+static bool shutdown_device_async(struct device *dev)
+{
+	if (async_schedule_dev_nocall(async_shutdown_handler, dev))
+		return true;
+	return false;
+}
+
+
+static void early_async_shutdown_devices(void)
+{
+	struct device *dev, *next, *needs_put = NULL;
+
+	if (!async_shutdown)
+		return;
+
+	spin_lock(&devices_kset->list_lock);
+
+	list_for_each_entry_safe_reverse(dev, next, &devices_kset->list,
+					 kobj.entry) {
+		if (wants_async_shutdown(dev)) {
+			get_device(dev);
+
+			if (shutdown_device_async(dev)) {
+				list_del_init(&dev->kobj.entry);
+			} else {
+				/*
+				 * async failed, clean up extra references
+				 * and run from the standard shutdown loop
+				 */
+				needs_put = dev;
+				break;
+			}
+		}
+	}
+
+	spin_unlock(&devices_kset->list_lock);
+
+	if (needs_put)
+		put_device(needs_put);
+}
+
 /**
  * device_shutdown - call ->shutdown() on each device to shutdown.
  */
@@ -4851,6 +4939,12 @@ void device_shutdown(void)
 
 	cpufreq_suspend();
 
+	/*
+	 * Start async device threads where possible to maximize potential
+	 * parallelism and minimize false dependency on unrelated sync devices
+	 */
+	early_async_shutdown_devices();
+
 	spin_lock(&devices_kset->list_lock);
 	/*
 	 * Walk the devices list backward, shutting down each in turn.
@@ -4869,11 +4963,16 @@ void device_shutdown(void)
 		list_del_init(&dev->kobj.entry);
 		spin_unlock(&devices_kset->list_lock);
 
-		shutdown_one_device(dev);
+		if (!wants_async_shutdown(dev) || !shutdown_device_async(dev)) {
+			wait_for_shutdown_dependencies(dev, false);
+			shutdown_one_device(dev);
+		}
 
 		spin_lock(&devices_kset->list_lock);
 	}
 	spin_unlock(&devices_kset->list_lock);
+
+	async_synchronize_full();
 }
 
 /*
diff --git a/include/linux/device.h b/include/linux/device.h
index d54c86d77764..0f2aeba34483 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -546,6 +546,7 @@ enum struct_device_flags {
 	DEV_FLAG_OF_NODE_REUSED = 7,
 	DEV_FLAG_OFFLINE_DISABLED = 8,
 	DEV_FLAG_OFFLINE = 9,
+	DEV_FLAG_ASYNC_SHUTDOWN = 10,
 
 	DEV_FLAG_COUNT
 };
@@ -763,6 +764,7 @@ __create_dev_flag_accessors(dma_coherent, DEV_FLAG_DMA_COHERENT);
 __create_dev_flag_accessors(of_node_reused, DEV_FLAG_OF_NODE_REUSED);
 __create_dev_flag_accessors(offline_disabled, DEV_FLAG_OFFLINE_DISABLED);
 __create_dev_flag_accessors(offline, DEV_FLAG_OFFLINE);
+__create_dev_flag_accessors(async_shutdown, DEV_FLAG_ASYNC_SHUTDOWN);
 
 #undef __create_dev_flag_accessors
 
-- 
2.53.0

[PATCH 4/5] PCI: Enable async shutdown support

[David Jeffery]

Like its async suspend support, allow PCI device shutdown to be performed
asynchronously to reduce shutdown time.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Tarun Sahu <tarunsahu@google.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/probe.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b63cd0c310bc..7cf3dabc885e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1045,6 +1045,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 
 	bus->bridge = get_device(&bridge->dev);
 	device_enable_async_suspend(bus->bridge);
+	dev_set_async_shutdown(bus->bridge);
 	pci_set_bus_of_node(bus);
 	pci_set_bus_msi_domain(bus);
 	if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) &&
@@ -2753,6 +2754,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 	pci_reassigndev_resource_alignment(dev);
 
 	pci_init_capabilities(dev);
+	dev_set_async_shutdown(&dev->dev);
 
 	/*
 	 * Add the device to our list of discovered devices
-- 
2.53.0

[PATCH 5/5] scsi: Enable async shutdown support

[David Jeffery]

Like scsi's async suspend support, allow scsi devices to be shut down
asynchronously to reduce system shutdown time.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
---
 drivers/scsi/hosts.c      | 2 ++
 drivers/scsi/scsi_sysfs.c | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index e047747d4ecf..bf691acc7a67 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -273,6 +273,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 	pm_runtime_set_active(&shost->shost_gendev);
 	pm_runtime_enable(&shost->shost_gendev);
 	device_enable_async_suspend(&shost->shost_gendev);
+	dev_set_async_shutdown(&shost->shost_gendev);
 
 	error = device_add(&shost->shost_gendev);
 	if (error)
@@ -282,6 +283,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 	get_device(shost->shost_gendev.parent);
 
 	device_enable_async_suspend(&shost->shost_dev);
+	dev_set_async_shutdown(&shost->shost_dev);
 
 	get_device(&shost->shost_gendev);
 	error = device_add(&shost->shost_dev);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index dfc3559e7e04..8fd317aef37b 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1386,6 +1386,7 @@ static int scsi_target_add(struct scsi_target *starget)
 	pm_runtime_set_active(&starget->dev);
 	pm_runtime_enable(&starget->dev);
 	device_enable_async_suspend(&starget->dev);
+	dev_set_async_shutdown(&starget->dev);
 
 	return 0;
 }
@@ -1412,6 +1413,7 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
 	transport_configure_device(&starget->dev);
 
 	device_enable_async_suspend(&sdev->sdev_gendev);
+	dev_set_async_shutdown(&sdev->sdev_gendev);
 	scsi_autopm_get_target(starget);
 	pm_runtime_set_active(&sdev->sdev_gendev);
 	if (!sdev->rpm_autosuspend)
@@ -1431,6 +1433,7 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
 	}
 
 	device_enable_async_suspend(&sdev->sdev_dev);
+	dev_set_async_shutdown(&sdev->sdev_dev);
 	error = device_add(&sdev->sdev_dev);
 	if (error) {
 		sdev_printk(KERN_INFO, sdev,
-- 
2.53.0

Re: [PATCH v16 0/5] shut down devices asynchronously

[Danilo Krummrich]

On Mon May 18, 2026 at 9:31 PM CEST, David Jeffery wrote:
> These patches are now rebased against the driver-core tree's driver-core-next
> branch.

[...]

> Changes from V15:
>
> The async_shutdown bit field is converted to a device flags bit Convert all
> patches to use the flag bit accessor macros to set or check if async shutdown
> should be used Added documentation on the kernel parameter to control use of
> async shutdown

Did you have a look at the Sashiko report from v15 [1]? Some of the concerns
raised seem valid at a quick glance.

(It seems that this version has not been picked up by Sashiko (despite you
mentioning they are based on driver-core-next). I'd assume it doesn't like that
the series was not sent with '--base'.)

Can you have a look at [1] please?

Thanks,
Danilo

[1] https://sashiko.dev/#/patchset/20260429175016.7915-1-djeffery%40redhat.com

> Stuart Hayes (2):
>   driver core: separate function to shutdown one device
>   driver core: do not always lock parent in shutdown
>
> David Jeffery (3):
>   driver core: async device shutdown infrastructure
>   PCI: Enable async shutdown support
>   scsi: Enable async shutdown support

Not sure it will make it for 7.2, but I think it would be good to give this some
more time in linux-next anyways.

Bjorn, James, Martin:

Should the PCI and scsi patch go through the driver-core tree too?

Do you prefer a signed tag with the driver-core changes to merge into the PCI
and scsi trees?

Re: [PATCH v16 0/5] shut down devices asynchronously

[David Jeffery]

On Mon, Jun 1, 2026 at 11:10 AM Danilo Krummrich <dakr@kernel.org> wrote:
>
> On Mon May 18, 2026 at 9:31 PM CEST, David Jeffery wrote:
> > These patches are now rebased against the driver-core tree's driver-core-next
> > branch.
>
> [...]
>
> > Changes from V15:
> >
> > The async_shutdown bit field is converted to a device flags bit Convert all
> > patches to use the flag bit accessor macros to set or check if async shutdown
> > should be used Added documentation on the kernel parameter to control use of
> > async shutdown
>
> Did you have a look at the Sashiko report from v15 [1]? Some of the concerns
> raised seem valid at a quick glance.
>
> (It seems that this version has not been picked up by Sashiko (despite you
> mentioning they are based on driver-core-next). I'd assume it doesn't like that
> the series was not sent with '--base'.)
>
> Can you have a look at [1] please?
>
> Thanks,
> Danilo
>
> [1] https://sashiko.dev/#/patchset/20260429175016.7915-1-djeffery%40redhat.com

This does look to have found some legitimate issues in need of
correction. I'll get them fixed.

Thanks,
David Jeffery