[PATCH v9 0/4] Introduce and plumb PMSG_POWEROFF

[PATCH v9 0/4] Introduce and plumb PMSG_POWEROFF

[Mario Limonciello (AMD)]

I've been working on a series that uses the hibernate flows (S4)
during shutdown (S5) [1], but it's a bit risky because it has changes
all around the kernel.  To mitigate risk Rafael suggested [2] to split
the series into at least 3 parts across different kernel cycles.

Here is the first part, which just introduces a PMSG_POWEROFF event
and uses it in any driver that manipulates PM events.

There are no functional changes for these changes and this series is
intended for 6.19.

v8->v9:
 * Reword commit messages (Bjorn)
 * Apply on top of 6.18-rc2 kernel base

Link: https://lore.kernel.org/linux-pm/20250909191619.2580169-1-superm1@kernel.org/ [1]
Link: https://lore.kernel.org/linux-pm/CAJZ5v0jHKp7c7dSQMZr5tmQOV6=fHOygTf-YG6Gx9YmurA9cTA@mail.gmail.com/ [2]

Mario Limonciello (AMD) (4):
  PM: Introduce new PMSG_POWEROFF event
  scsi: Add PM_EVENT_POWEROFF into suspend callbacks
  usb: sl811-hcd: Add PM_EVENT_POWEROFF into suspend callbacks
  USB: Pass PMSG_POWEROFF event to suspend_common()

 drivers/base/power/main.c    |  7 +++++++
 drivers/scsi/mesh.c          |  1 +
 drivers/scsi/stex.c          |  1 +
 drivers/usb/core/hcd-pci.c   | 11 ++++++++++-
 drivers/usb/host/sl811-hcd.c |  1 +
 include/linux/pm.h           |  3 +++
 include/trace/events/power.h |  3 ++-
 7 files changed, 25 insertions(+), 2 deletions(-)

-- 
2.43.0

[PATCH v9 1/4] PM: Introduce new PMSG_POWEROFF event

[Mario Limonciello (AMD)]

PMSG_POWEROFF will be used for the PM core to allow differentiating between
a hibernation or shutdown sequence when re-using callbacks for common code.

Hibernation is started by writing a hibernation method (such as 'platform'
'shutdown', or 'reboot') to use into /sys/power/disk and writing 'disk' to
/sys/power/state.

Shutdown is initiated with the reboot() syscall with arguments on whether
to halt the system or power it off.

Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v9:
 * Add more detail to commit message (Bjorn)
v8:
 * Break series into 3 parts
 * Drop PMSG_NO_WAKEUP change
v7:
 * Reword commit
v5:
 * Re-order and split
 * Add tags
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/base/power/main.c    | 7 +++++++
 include/linux/pm.h           | 3 +++
 include/trace/events/power.h | 3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 451d54486645b..ecdd88b578a04 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -95,6 +95,8 @@ static const char *pm_verb(int event)
 		return "restore";
 	case PM_EVENT_RECOVER:
 		return "recover";
+	case PM_EVENT_POWEROFF:
+		return "poweroff";
 	default:
 		return "(unknown PM event)";
 	}
@@ -367,6 +369,7 @@ static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff;
 	case PM_EVENT_THAW:
@@ -401,6 +404,7 @@ static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_late;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_late;
 	case PM_EVENT_THAW:
@@ -435,6 +439,7 @@ static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t stat
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_noirq;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_noirq;
 	case PM_EVENT_THAW:
@@ -1385,6 +1390,8 @@ static pm_message_t resume_event(pm_message_t sleep_state)
 		return PMSG_RECOVER;
 	case PM_EVENT_HIBERNATE:
 		return PMSG_RESTORE;
+	case PM_EVENT_POWEROFF:
+		return PMSG_ON;
 	}
 	return PMSG_ON;
 }
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 52ee38d72aa23..564133e53f0d3 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -507,6 +507,7 @@ const struct dev_pm_ops name = { \
  * RECOVER	Creation of a hibernation image or restoration of the main
  *		memory contents from a hibernation image has failed, call
  *		->thaw() and ->complete() for all devices.
+ * POWEROFF	System will poweroff, call ->poweroff() for all devices.
  *
  * The following PM_EVENT_ messages are defined for internal use by
  * kernel subsystems.  They are never issued by the PM core.
@@ -537,6 +538,7 @@ const struct dev_pm_ops name = { \
 #define PM_EVENT_USER		0x0100
 #define PM_EVENT_REMOTE		0x0200
 #define PM_EVENT_AUTO		0x0400
+#define PM_EVENT_POWEROFF	0x0800
 
 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
@@ -551,6 +553,7 @@ const struct dev_pm_ops name = { \
 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
+#define PMSG_POWEROFF	((struct pm_message){ .event = PM_EVENT_POWEROFF, })
 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index 82904291c2b81..370f8df2fdb4b 100644
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -179,7 +179,8 @@ TRACE_EVENT(pstate_sample,
 		{ PM_EVENT_HIBERNATE, "hibernate" }, \
 		{ PM_EVENT_THAW, "thaw" }, \
 		{ PM_EVENT_RESTORE, "restore" }, \
-		{ PM_EVENT_RECOVER, "recover" })
+		{ PM_EVENT_RECOVER, "recover" }, \
+		{ PM_EVENT_POWEROFF, "poweroff" })
 
 DEFINE_EVENT(cpu, cpu_frequency,
 
-- 
2.43.0

[PATCH v9 2/4] scsi: Add PM_EVENT_POWEROFF into suspend callbacks

[Mario Limonciello (AMD)]

If the PM core uses hibernation callbacks for powering off the
system, drivers will receive PM_EVENT_POWEROFF and should handle
it the same as they previously handled PM_EVENT_HIBERNATE.

Support this case in the scsi driver.  No functional changes.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v9:
 * Reword commit (Bjorn)
v8:
 * Break up series to 3 parts
 * Pick up tag
v5:
 * Re-order
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/scsi/mesh.c | 1 +
 drivers/scsi/stex.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
index 1c15cac41d805..768b85eecc8fd 100644
--- a/drivers/scsi/mesh.c
+++ b/drivers/scsi/mesh.c
@@ -1762,6 +1762,7 @@ static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
 	case PM_EVENT_SUSPEND:
 	case PM_EVENT_HIBERNATE:
 	case PM_EVENT_FREEZE:
+	case PM_EVENT_POWEROFF:
 		break;
 	default:
 		return 0;
diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index d8ad02c293205..e6357bc301cb9 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -1965,6 +1965,7 @@ static int stex_choice_sleep_mic(struct st_hba *hba, pm_message_t state)
 	case PM_EVENT_SUSPEND:
 		return ST_S3;
 	case PM_EVENT_HIBERNATE:
+	case PM_EVENT_POWEROFF:
 		hba->msi_lock = 0;
 		return ST_S4;
 	default:
-- 
2.43.0

[PATCH v9 3/4] usb: sl811-hcd: Add PM_EVENT_POWEROFF into suspend callbacks

[Mario Limonciello (AMD)]

When the ACPI core uses hibernation callbacks for shutdown drivers
will receive PM_EVENT_POWEROFF and should handle it the same as
PM_EVENT_HIBERNATE would have been used.

Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v8:
 * Break up series to 3 parts
v5:
 * Re-order
 * Add tags
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/usb/host/sl811-hcd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/host/sl811-hcd.c b/drivers/usb/host/sl811-hcd.c
index ea3cab99c5d40..5d6dba681e503 100644
--- a/drivers/usb/host/sl811-hcd.c
+++ b/drivers/usb/host/sl811-hcd.c
@@ -1748,6 +1748,7 @@ sl811h_suspend(struct platform_device *dev, pm_message_t state)
 		break;
 	case PM_EVENT_SUSPEND:
 	case PM_EVENT_HIBERNATE:
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_PRETHAW:		/* explicitly discard hw state */
 		port_power(sl811, 0);
 		break;
-- 
2.43.0

[PATCH v9 4/4] USB: Pass PMSG_POWEROFF event to suspend_common()

[Mario Limonciello (AMD)]

suspend_common() passes a PM message indicating what type of event
is occurring.  PMSG_POWEROFF is intended to be used when hibernate
callbacks were utilized for turning off the system.

Add a new callback hcd_pci_poweroff() which will
determine if target state is power off and pass PMSG_POWEROFF as the
message.

suspend_common() doesn't do any special handling with this case at
the moment, so there are no functional changes in this patch.

Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v9:
 * Reword commit message (Bjorn)
v8:
 * Drop SYSTEM_HALT case
v7:
 * Reword commit mesasge
v6:
 * Fix LKP robot issue without CONFIG_PM_SLEEP
v5:
 * New patch
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/usb/core/hcd-pci.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index cd223475917ef..959baccfb07d1 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -6,6 +6,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/pm.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
 
@@ -531,6 +532,13 @@ static int hcd_pci_freeze(struct device *dev)
 	return suspend_common(dev, PMSG_FREEZE);
 }
 
+static int hcd_pci_poweroff(struct device *dev)
+{
+	if (system_state == SYSTEM_POWER_OFF)
+		return suspend_common(dev, PMSG_POWEROFF);
+	return suspend_common(dev, PMSG_SUSPEND);
+}
+
 static int hcd_pci_suspend_noirq(struct device *dev)
 {
 	struct pci_dev		*pci_dev = to_pci_dev(dev);
@@ -602,6 +610,7 @@ static int hcd_pci_restore(struct device *dev)
 #define hcd_pci_suspend		NULL
 #define hcd_pci_freeze			NULL
 #define hcd_pci_suspend_noirq	NULL
+#define hcd_pci_poweroff	NULL
 #define hcd_pci_poweroff_late	NULL
 #define hcd_pci_resume_noirq	NULL
 #define hcd_pci_resume		NULL
@@ -639,7 +648,7 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
 	.freeze_noirq	= check_root_hub_suspended,
 	.thaw_noirq	= NULL,
 	.thaw		= hcd_pci_resume,
-	.poweroff	= hcd_pci_suspend,
+	.poweroff	= hcd_pci_poweroff,
 	.poweroff_late	= hcd_pci_poweroff_late,
 	.poweroff_noirq	= hcd_pci_suspend_noirq,
 	.restore_noirq	= hcd_pci_resume_noirq,
-- 
2.43.0

Re: [PATCH v9 4/4] USB: Pass PMSG_POWEROFF event to suspend_common()

[Rafael J. Wysocki]

On Sun, Oct 26, 2025 at 6:09 AM Mario Limonciello (AMD)
<superm1@kernel.org> wrote:
>
> suspend_common() passes a PM message indicating what type of event
> is occurring.  PMSG_POWEROFF is intended to be used when hibernate
> callbacks were utilized for turning off the system.
>
> Add a new callback hcd_pci_poweroff() which will
> determine if target state is power off and pass PMSG_POWEROFF as the
> message.
>
> suspend_common() doesn't do any special handling with this case at
> the moment, so there are no functional changes in this patch.
>
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
> v9:
>  * Reword commit message (Bjorn)
> v8:
>  * Drop SYSTEM_HALT case
> v7:
>  * Reword commit mesasge
> v6:
>  * Fix LKP robot issue without CONFIG_PM_SLEEP
> v5:
>  * New patch
> v4:
>  * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
> ---
>  drivers/usb/core/hcd-pci.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> index cd223475917ef..959baccfb07d1 100644
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -6,6 +6,7 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/pci.h>
> +#include <linux/pm.h>
>  #include <linux/usb.h>
>  #include <linux/usb/hcd.h>
>
> @@ -531,6 +532,13 @@ static int hcd_pci_freeze(struct device *dev)
>         return suspend_common(dev, PMSG_FREEZE);
>  }
>
> +static int hcd_pci_poweroff(struct device *dev)
> +{
> +       if (system_state == SYSTEM_POWER_OFF)
> +               return suspend_common(dev, PMSG_POWEROFF);
> +       return suspend_common(dev, PMSG_SUSPEND);
> +}
> +
>  static int hcd_pci_suspend_noirq(struct device *dev)
>  {
>         struct pci_dev          *pci_dev = to_pci_dev(dev);
> @@ -602,6 +610,7 @@ static int hcd_pci_restore(struct device *dev)
>  #define hcd_pci_suspend                NULL
>  #define hcd_pci_freeze                 NULL
>  #define hcd_pci_suspend_noirq  NULL
> +#define hcd_pci_poweroff       NULL
>  #define hcd_pci_poweroff_late  NULL
>  #define hcd_pci_resume_noirq   NULL
>  #define hcd_pci_resume         NULL
> @@ -639,7 +648,7 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
>         .freeze_noirq   = check_root_hub_suspended,
>         .thaw_noirq     = NULL,
>         .thaw           = hcd_pci_resume,
> -       .poweroff       = hcd_pci_suspend,
> +       .poweroff       = hcd_pci_poweroff,
>         .poweroff_late  = hcd_pci_poweroff_late,
>         .poweroff_noirq = hcd_pci_suspend_noirq,
>         .restore_noirq  = hcd_pci_resume_noirq,
> --

I would defer this patch until you know what exactly suspend_common()
will do for PMSG_POWEROFF because it may just be simpler to check
system_state == SYSTEM_POWER_OFF in it internally.

Re: [PATCH v9 4/4] USB: Pass PMSG_POWEROFF event to suspend_common()

[Mario Limonciello (AMD) (kernel.org)]

On 11/3/2025 2:09 PM, Rafael J. Wysocki wrote:
> On Sun, Oct 26, 2025 at 6:09 AM Mario Limonciello (AMD)
> <superm1@kernel.org> wrote:
>>
>> suspend_common() passes a PM message indicating what type of event
>> is occurring.  PMSG_POWEROFF is intended to be used when hibernate
>> callbacks were utilized for turning off the system.
>>
>> Add a new callback hcd_pci_poweroff() which will
>> determine if target state is power off and pass PMSG_POWEROFF as the
>> message.
>>
>> suspend_common() doesn't do any special handling with this case at
>> the moment, so there are no functional changes in this patch.
>>
>> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
>> ---
>> v9:
>>   * Reword commit message (Bjorn)
>> v8:
>>   * Drop SYSTEM_HALT case
>> v7:
>>   * Reword commit mesasge
>> v6:
>>   * Fix LKP robot issue without CONFIG_PM_SLEEP
>> v5:
>>   * New patch
>> v4:
>>   * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
>> ---
>>   drivers/usb/core/hcd-pci.c | 11 ++++++++++-
>>   1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
>> index cd223475917ef..959baccfb07d1 100644
>> --- a/drivers/usb/core/hcd-pci.c
>> +++ b/drivers/usb/core/hcd-pci.c
>> @@ -6,6 +6,7 @@
>>   #include <linux/kernel.h>
>>   #include <linux/module.h>
>>   #include <linux/pci.h>
>> +#include <linux/pm.h>
>>   #include <linux/usb.h>
>>   #include <linux/usb/hcd.h>
>>
>> @@ -531,6 +532,13 @@ static int hcd_pci_freeze(struct device *dev)
>>          return suspend_common(dev, PMSG_FREEZE);
>>   }
>>
>> +static int hcd_pci_poweroff(struct device *dev)
>> +{
>> +       if (system_state == SYSTEM_POWER_OFF)
>> +               return suspend_common(dev, PMSG_POWEROFF);
>> +       return suspend_common(dev, PMSG_SUSPEND);
>> +}
>> +
>>   static int hcd_pci_suspend_noirq(struct device *dev)
>>   {
>>          struct pci_dev          *pci_dev = to_pci_dev(dev);
>> @@ -602,6 +610,7 @@ static int hcd_pci_restore(struct device *dev)
>>   #define hcd_pci_suspend                NULL
>>   #define hcd_pci_freeze                 NULL
>>   #define hcd_pci_suspend_noirq  NULL
>> +#define hcd_pci_poweroff       NULL
>>   #define hcd_pci_poweroff_late  NULL
>>   #define hcd_pci_resume_noirq   NULL
>>   #define hcd_pci_resume         NULL
>> @@ -639,7 +648,7 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
>>          .freeze_noirq   = check_root_hub_suspended,
>>          .thaw_noirq     = NULL,
>>          .thaw           = hcd_pci_resume,
>> -       .poweroff       = hcd_pci_suspend,
>> +       .poweroff       = hcd_pci_poweroff,
>>          .poweroff_late  = hcd_pci_poweroff_late,
>>          .poweroff_noirq = hcd_pci_suspend_noirq,
>>          .restore_noirq  = hcd_pci_resume_noirq,
>> --
> 
> I would defer this patch until you know what exactly suspend_common()
> will do for PMSG_POWEROFF because it may just be simpler to check
> system_state == SYSTEM_POWER_OFF in it internally.

OK - in that case would you just take the first 3 for 6.19?

Re: [PATCH v9 4/4] USB: Pass PMSG_POWEROFF event to suspend_common()

[Rafael J. Wysocki]

On Mon, Nov 3, 2025 at 9:10 PM Mario Limonciello (AMD) (kernel.org)
<superm1@kernel.org> wrote:
>
>
>
> On 11/3/2025 2:09 PM, Rafael J. Wysocki wrote:
> > On Sun, Oct 26, 2025 at 6:09 AM Mario Limonciello (AMD)
> > <superm1@kernel.org> wrote:
> >>
> >> suspend_common() passes a PM message indicating what type of event
> >> is occurring.  PMSG_POWEROFF is intended to be used when hibernate
> >> callbacks were utilized for turning off the system.
> >>
> >> Add a new callback hcd_pci_poweroff() which will
> >> determine if target state is power off and pass PMSG_POWEROFF as the
> >> message.
> >>
> >> suspend_common() doesn't do any special handling with this case at
> >> the moment, so there are no functional changes in this patch.
> >>
> >> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> >> ---
> >> v9:
> >>   * Reword commit message (Bjorn)
> >> v8:
> >>   * Drop SYSTEM_HALT case
> >> v7:
> >>   * Reword commit mesasge
> >> v6:
> >>   * Fix LKP robot issue without CONFIG_PM_SLEEP
> >> v5:
> >>   * New patch
> >> v4:
> >>   * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
> >> ---
> >>   drivers/usb/core/hcd-pci.c | 11 ++++++++++-
> >>   1 file changed, 10 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> >> index cd223475917ef..959baccfb07d1 100644
> >> --- a/drivers/usb/core/hcd-pci.c
> >> +++ b/drivers/usb/core/hcd-pci.c
> >> @@ -6,6 +6,7 @@
> >>   #include <linux/kernel.h>
> >>   #include <linux/module.h>
> >>   #include <linux/pci.h>
> >> +#include <linux/pm.h>
> >>   #include <linux/usb.h>
> >>   #include <linux/usb/hcd.h>
> >>
> >> @@ -531,6 +532,13 @@ static int hcd_pci_freeze(struct device *dev)
> >>          return suspend_common(dev, PMSG_FREEZE);
> >>   }
> >>
> >> +static int hcd_pci_poweroff(struct device *dev)
> >> +{
> >> +       if (system_state == SYSTEM_POWER_OFF)
> >> +               return suspend_common(dev, PMSG_POWEROFF);
> >> +       return suspend_common(dev, PMSG_SUSPEND);
> >> +}
> >> +
> >>   static int hcd_pci_suspend_noirq(struct device *dev)
> >>   {
> >>          struct pci_dev          *pci_dev = to_pci_dev(dev);
> >> @@ -602,6 +610,7 @@ static int hcd_pci_restore(struct device *dev)
> >>   #define hcd_pci_suspend                NULL
> >>   #define hcd_pci_freeze                 NULL
> >>   #define hcd_pci_suspend_noirq  NULL
> >> +#define hcd_pci_poweroff       NULL
> >>   #define hcd_pci_poweroff_late  NULL
> >>   #define hcd_pci_resume_noirq   NULL
> >>   #define hcd_pci_resume         NULL
> >> @@ -639,7 +648,7 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
> >>          .freeze_noirq   = check_root_hub_suspended,
> >>          .thaw_noirq     = NULL,
> >>          .thaw           = hcd_pci_resume,
> >> -       .poweroff       = hcd_pci_suspend,
> >> +       .poweroff       = hcd_pci_poweroff,
> >>          .poweroff_late  = hcd_pci_poweroff_late,
> >>          .poweroff_noirq = hcd_pci_suspend_noirq,
> >>          .restore_noirq  = hcd_pci_resume_noirq,
> >> --
> >
> > I would defer this patch until you know what exactly suspend_common()
> > will do for PMSG_POWEROFF because it may just be simpler to check
> > system_state == SYSTEM_POWER_OFF in it internally.
>
> OK - in that case would you just take the first 3 for 6.19?

I still need to go through them once again, but overall that's the plan.

Re: [PATCH v9 1/4] PM: Introduce new PMSG_POWEROFF event

[Rafael J. Wysocki]

On Sun, Oct 26, 2025 at 6:09 AM Mario Limonciello (AMD)
<superm1@kernel.org> wrote:
>
> PMSG_POWEROFF will be used for the PM core to allow differentiating between
> a hibernation or shutdown sequence when re-using callbacks for common code.
>
> Hibernation is started by writing a hibernation method (such as 'platform'
> 'shutdown', or 'reboot') to use into /sys/power/disk and writing 'disk' to
> /sys/power/state.
>
> Shutdown is initiated with the reboot() syscall with arguments on whether
> to halt the system or power it off.
>
> Tested-by: Eric Naim <dnaim@cachyos.org>
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
> v9:
>  * Add more detail to commit message (Bjorn)
> v8:
>  * Break series into 3 parts
>  * Drop PMSG_NO_WAKEUP change
> v7:
>  * Reword commit
> v5:
>  * Re-order and split
>  * Add tags
> v4:
>  * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
> ---
>  drivers/base/power/main.c    | 7 +++++++
>  include/linux/pm.h           | 3 +++
>  include/trace/events/power.h | 3 ++-
>  3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index 451d54486645b..ecdd88b578a04 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -95,6 +95,8 @@ static const char *pm_verb(int event)
>                 return "restore";
>         case PM_EVENT_RECOVER:
>                 return "recover";
> +       case PM_EVENT_POWEROFF:
> +               return "poweroff";
>         default:
>                 return "(unknown PM event)";
>         }
> @@ -367,6 +369,7 @@ static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
>         case PM_EVENT_FREEZE:
>         case PM_EVENT_QUIESCE:
>                 return ops->freeze;
> +       case PM_EVENT_POWEROFF:
>         case PM_EVENT_HIBERNATE:
>                 return ops->poweroff;
>         case PM_EVENT_THAW:
> @@ -401,6 +404,7 @@ static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
>         case PM_EVENT_FREEZE:
>         case PM_EVENT_QUIESCE:
>                 return ops->freeze_late;
> +       case PM_EVENT_POWEROFF:
>         case PM_EVENT_HIBERNATE:
>                 return ops->poweroff_late;
>         case PM_EVENT_THAW:
> @@ -435,6 +439,7 @@ static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t stat
>         case PM_EVENT_FREEZE:
>         case PM_EVENT_QUIESCE:
>                 return ops->freeze_noirq;
> +       case PM_EVENT_POWEROFF:
>         case PM_EVENT_HIBERNATE:
>                 return ops->poweroff_noirq;
>         case PM_EVENT_THAW:
> @@ -1385,6 +1390,8 @@ static pm_message_t resume_event(pm_message_t sleep_state)
>                 return PMSG_RECOVER;
>         case PM_EVENT_HIBERNATE:
>                 return PMSG_RESTORE;
> +       case PM_EVENT_POWEROFF:
> +               return PMSG_ON;

I'm not sure if PMSG_ON is the right choice here (as stated elsewhere,
the "poweroff" transition at the end of system shutdown cannot really
be rolled back and this is all about what pm_message_t value to use
for the rollback), but even so, this change is unnecessary because
PMSG_ON is returned by default.

>         }
>         return PMSG_ON;
>  }