[PATCH v5 0/3] Support power resources defined in acpi on ata

[PATCH v5 0/3] Support power resources defined in acpi on ata

[Markus Probst]

This series adds support for power resources defined in acpi on ata
ports/devices. A device can define a power resource in an ata port/device,
which then gets powered on right before the port is probed. This can be
useful for devices, which have sata power connectors that are:
  a: powered down by default
  b: can be individually powered on
like in some synology nas devices. If thats the case it will be assumed,
that the power resource won't survive reboots and therefore the disk will
be stopped.

Changes since v4:
- improved documentation
- use false/true instead of 0/1
- removed repeating code in ata_acpi_dev_manage_restart
- split long lines
- removed debug message
- improved error message

Changes since v3:
- rename function from "ata_port_set_power_state"
  to "ata_acpi_port_power_on" and remove enable argument
- split "ata_acpi_port_power_on" and "ata_acpi_dev_manage_restart" into
  two commits
- improved commit messages
- improved comments (style and new comments)

Changes since v2:
- improved commit messages
- addressed warning from kernel test robot

Changes since v1:
- improved commit messages
- addressed style issues (too long lines and docs)
- removed ata_dev_manage_restart() and ata_port_set_power_state()
  methods
- improved log messages in ata_acpi_port_set_power_state


Markus Probst (3):
  scsi: sd: Add manage_restart device attribute to scsi_disk
  ata: stop disk on restart if ACPI power resources are found
  ata: Use ACPI methods to power on disks

 drivers/ata/libata-acpi.c  | 66 ++++++++++++++++++++++++++++++++++++++
 drivers/ata/libata-core.c  |  2 ++
 drivers/ata/libata-scsi.c  |  1 +
 drivers/ata/libata.h       |  4 +++
 drivers/scsi/sd.c          | 35 +++++++++++++++++++-
 include/scsi/scsi_device.h |  6 ++++
 6 files changed, 113 insertions(+), 1 deletion(-)

-- 
2.51.0

[PATCH v5 1/3] scsi: sd: Add manage_restart device attribute to scsi_disk

[Markus Probst]

In addition to the already existing manage_shutdown,
manage_system_start_stop and manage_runtime_start_stop device
scsi_disk attributes, add manage_restart, which allows the high-level
device driver (sd) to manage the device power state for SYSTEM_RESTART if
set to 1.

This attribute is necessary for the following commit "ata: stop disk on
restart if ACPI power resources are found" to avoid a potential disk power
failure in the case the SATA power connector does not retain the power
state after a restart.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
 drivers/scsi/sd.c          | 35 ++++++++++++++++++++++++++++++++++-
 include/scsi/scsi_device.h |  6 ++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0252d3f6bed1..2ea244d6f998 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -318,6 +318,36 @@ static ssize_t manage_shutdown_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(manage_shutdown);
 
+static ssize_t manage_restart_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+	struct scsi_device *sdp = sdkp->device;
+
+	return sysfs_emit(buf, "%u\n", sdp->manage_restart);
+}
+
+
+static ssize_t manage_restart_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+	struct scsi_device *sdp = sdkp->device;
+	bool v;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (kstrtobool(buf, &v))
+		return -EINVAL;
+
+	sdp->manage_restart = v;
+
+	return count;
+}
+static DEVICE_ATTR_RW(manage_restart);
+
 static ssize_t
 allow_restart_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -654,6 +684,7 @@ static struct attribute *sd_disk_attrs[] = {
 	&dev_attr_manage_system_start_stop.attr,
 	&dev_attr_manage_runtime_start_stop.attr,
 	&dev_attr_manage_shutdown.attr,
+	&dev_attr_manage_restart.attr,
 	&dev_attr_protection_type.attr,
 	&dev_attr_protection_mode.attr,
 	&dev_attr_app_tag_own.attr,
@@ -4177,7 +4208,9 @@ static void sd_shutdown(struct device *dev)
 	    (system_state == SYSTEM_POWER_OFF &&
 	     sdkp->device->manage_shutdown) ||
 	    (system_state == SYSTEM_RUNNING &&
-	     sdkp->device->manage_runtime_start_stop)) {
+	     sdkp->device->manage_runtime_start_stop) ||
+	    (system_state == SYSTEM_RESTART &&
+	     sdkp->device->manage_restart)) {
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		sd_start_stop_device(sdkp, 0);
 	}
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 6d6500148c4b..c7e657ac8b6d 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -178,6 +178,12 @@ struct scsi_device {
 	 */
 	unsigned manage_shutdown:1;
 
+	/*
+	 * If true, let the high-level device driver (sd) manage the device
+	 * power state for system restart (reboot) operations.
+	 */
+	unsigned manage_restart:1;
+
 	/*
 	 * If set and if the device is runtime suspended, ask the high-level
 	 * device driver (sd) to force a runtime resume of the device.
-- 
2.51.0

Re: [PATCH v5 1/3] scsi: sd: Add manage_restart device attribute to scsi_disk

[Damien Le Moal]

On 10/28/25 5:23 AM, Markus Probst wrote:
> In addition to the already existing manage_shutdown,
> manage_system_start_stop and manage_runtime_start_stop device
> scsi_disk attributes, add manage_restart, which allows the high-level
> device driver (sd) to manage the device power state for SYSTEM_RESTART if
> set to 1.
> 
> This attribute is necessary for the following commit "ata: stop disk on
> restart if ACPI power resources are found" to avoid a potential disk power
> failure in the case the SATA power connector does not retain the power
> state after a restart.
> 
> Signed-off-by: Markus Probst <markus.probst@posteo.de>

One nit below.

With that fixed, looks OK to me.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

> +static ssize_t manage_restart_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	struct scsi_disk *sdkp = to_scsi_disk(dev);
> +	struct scsi_device *sdp = sdkp->device;
> +
> +	return sysfs_emit(buf, "%u\n", sdp->manage_restart);
> +}
> +
> +

One extra blank line not needed here.

> +static ssize_t manage_restart_store(struct device *dev,
> +				    struct device_attribute *attr,
> +				    const char *buf, size_t count)
> +{
> +	struct scsi_disk *sdkp = to_scsi_disk(dev);
> +	struct scsi_device *sdp = sdkp->device;
> +	bool v;

-- 
Damien Le Moal
Western Digital Research

[PATCH v5 2/3] ata: stop disk on restart if ACPI power resources are found

[Markus Probst]

Some embedded devices have the ability to control whether power is
provided to the disks via the SATA power connector or not. ACPI power
resources are usually off by default, thus making it unclear if the
specific power resource will retain its state after a restart. If power
resources are defined on ATA ports / devices in ACPI, we should stop the
disk on SYSTEM_RESTART, to ensure the disk will not lose power while
active.

Add a new function, ata_acpi_dev_manage_restart(), that will be used to
determine if a disk should be stopped before restarting the system. If a
usable ACPI power resource has been found, it is assumed that the disk
will lose power after a restart and should be stopped to avoid a power
failure.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
 drivers/ata/libata-acpi.c | 26 ++++++++++++++++++++++++++
 drivers/ata/libata-scsi.c |  1 +
 drivers/ata/libata.h      |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index f2140fc06ba0..196ca1227d09 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -245,6 +245,32 @@ void ata_acpi_bind_dev(struct ata_device *dev)
 				   ata_acpi_dev_uevent);
 }
 
+/**
+ * ata_acpi_dev_manage_restart - if the disk should be stopped (spun down) on
+ *                               system restart.
+ * @dev: target ATA device
+ *
+ * RETURNS:
+ * true if the disk should be stopped, otherwise false.
+ */
+bool ata_acpi_dev_manage_restart(struct ata_device *dev)
+{
+	struct device *tdev;
+
+	/*
+	 * If ATA_FLAG_ACPI_SATA is set, the acpi fwnode is attached to the
+	 * ata_device instead of the ata_port.
+	 */
+	if (dev->link->ap->flags & ATA_FLAG_ACPI_SATA)
+		tdev = &dev->tdev;
+	else
+		tdev = &dev->link->ap->tdev;
+
+	if (!is_acpi_device_node(tdev->fwnode))
+		return false;
+	return acpi_bus_power_manageable(ACPI_HANDLE(tdev));
+}
+
 /**
  * ata_acpi_dissociate - dissociate ATA host from ACPI objects
  * @host: target ATA host
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b43a3196e2be..026122bb6f2f 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1095,6 +1095,7 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct queue_limits *lim,
 		 */
 		sdev->manage_runtime_start_stop = 1;
 		sdev->manage_shutdown = 1;
+		sdev->manage_restart = ata_acpi_dev_manage_restart(dev);
 		sdev->force_runtime_start_on_system_start = 1;
 	}
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index e5b977a8d3e1..af08bb9b40d0 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -130,6 +130,7 @@ extern void ata_acpi_on_disable(struct ata_device *dev);
 extern void ata_acpi_set_state(struct ata_port *ap, pm_message_t state);
 extern void ata_acpi_bind_port(struct ata_port *ap);
 extern void ata_acpi_bind_dev(struct ata_device *dev);
+extern bool ata_acpi_dev_manage_restart(struct ata_device *dev);
 extern acpi_handle ata_dev_acpi_handle(struct ata_device *dev);
 #else
 static inline void ata_acpi_dissociate(struct ata_host *host) { }
@@ -140,6 +141,7 @@ static inline void ata_acpi_set_state(struct ata_port *ap,
 				      pm_message_t state) { }
 static inline void ata_acpi_bind_port(struct ata_port *ap) {}
 static inline void ata_acpi_bind_dev(struct ata_device *dev) {}
+static inline bool ata_acpi_dev_manage_restart(struct ata_device *dev) { return 0; }
 #endif
 
 /* libata-scsi.c */
-- 
2.51.0

Re: [PATCH v5 2/3] ata: stop disk on restart if ACPI power resources are found

[Damien Le Moal]

On 10/28/25 5:23 AM, Markus Probst wrote:
> Some embedded devices have the ability to control whether power is
> provided to the disks via the SATA power connector or not. ACPI power
> resources are usually off by default, thus making it unclear if the
> specific power resource will retain its state after a restart. If power
> resources are defined on ATA ports / devices in ACPI, we should stop the
> disk on SYSTEM_RESTART, to ensure the disk will not lose power while
> active.
> 
> Add a new function, ata_acpi_dev_manage_restart(), that will be used to
> determine if a disk should be stopped before restarting the system. If a
> usable ACPI power resource has been found, it is assumed that the disk
> will lose power after a restart and should be stopped to avoid a power
> failure.

I think you meant to say "to avoid unclean shutdown due to power loss." ?
Because this is not handling a power failure, but rather a power loss on
shutdown with the device still running, right ?

With that clarified, looks OK to me.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>


-- 
Damien Le Moal
Western Digital Research

[PATCH v5 3/3] ata: Use ACPI methods to power on disks

[Markus Probst]

Some embedded devices have the ability to control whether power is
provided to the disks via the SATA power connector or not. If power
resources are defined on ATA ports / devices in ACPI, we should try to set
the power state to D0 before probing the disk to ensure that any power
supply or power gate that may exist is providing power to the disk.

An example for such devices would be newer synology NAS devices. Every
disk slot has its own SATA power connector. Whether the connector is
providing power is controlled via an gpio, which is *off by default*.
Also the disk loses power on reboots.

Add a new function, ata_acpi_port_power_on(), that will be used to power
on the SATA power connector if usable ACPI power resources on the
associated ATA port / device are found. It will be called right before
probing the port, therefore the disk will be powered on just in time.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
 drivers/ata/libata-acpi.c | 40 +++++++++++++++++++++++++++++++++++++++
 drivers/ata/libata-core.c |  2 ++
 drivers/ata/libata.h      |  2 ++
 3 files changed, 44 insertions(+)

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 196ca1227d09..b0d70e075cd2 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -271,6 +271,46 @@ bool ata_acpi_dev_manage_restart(struct ata_device *dev)
 	return acpi_bus_power_manageable(ACPI_HANDLE(tdev));
 }
 
+/**
+ * ata_acpi_port_power_on - set the power state of the ata port to D0
+ * @ap: target ATA port
+ *
+ * This function is called at the beginning of ata_port_probe.
+ */
+void ata_acpi_port_power_on(struct ata_port *ap)
+{
+	acpi_handle handle;
+	int i;
+
+	/* If `ATA_FLAG_ACPI_SATA` is set, the acpi fwnode is attached to the
+	 * `ata_device` instead of the `ata_port`.
+	 */
+	if (ap->flags & ATA_FLAG_ACPI_SATA) {
+		for (i = 0; i < ATA_MAX_DEVICES; i++) {
+			struct ata_device *dev = &ap->link.device[i];
+
+			if (!is_acpi_device_node(dev->tdev.fwnode))
+				continue;
+			handle = ACPI_HANDLE(&dev->tdev);
+			if (!acpi_bus_power_manageable(handle))
+				continue;
+			if (acpi_bus_set_power(handle, ACPI_STATE_D0))
+				ata_dev_err(dev,
+					    "acpi: failed to power state to D0\n");
+		}
+		return;
+	}
+
+	if (!is_acpi_device_node(ap->tdev.fwnode))
+		return;
+	handle = ACPI_HANDLE(&ap->tdev);
+	if (!acpi_bus_power_manageable(handle))
+		return;
+
+	if (acpi_bus_set_power(handle, ACPI_STATE_D0))
+		ata_port_err(ap, "acpi: failed to set power state to D0\n");
+}
+
 /**
  * ata_acpi_dissociate - dissociate ATA host from ACPI objects
  * @host: target ATA host
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2a210719c4ce..a6813ced3ec2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5901,6 +5901,8 @@ void ata_port_probe(struct ata_port *ap)
 	struct ata_eh_info *ehi = &ap->link.eh_info;
 	unsigned long flags;
 
+	ata_acpi_port_power_on(ap);
+
 	/* kick EH for boot probing */
 	spin_lock_irqsave(ap->lock, flags);
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index af08bb9b40d0..0e7ecac73680 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -130,6 +130,7 @@ extern void ata_acpi_on_disable(struct ata_device *dev);
 extern void ata_acpi_set_state(struct ata_port *ap, pm_message_t state);
 extern void ata_acpi_bind_port(struct ata_port *ap);
 extern void ata_acpi_bind_dev(struct ata_device *dev);
+extern void ata_acpi_port_power_on(struct ata_port *ap);
 extern bool ata_acpi_dev_manage_restart(struct ata_device *dev);
 extern acpi_handle ata_dev_acpi_handle(struct ata_device *dev);
 #else
@@ -141,6 +142,7 @@ static inline void ata_acpi_set_state(struct ata_port *ap,
 				      pm_message_t state) { }
 static inline void ata_acpi_bind_port(struct ata_port *ap) {}
 static inline void ata_acpi_bind_dev(struct ata_device *dev) {}
+static inline void ata_acpi_port_power_on(struct ata_port *ap) {}
 static inline bool ata_acpi_dev_manage_restart(struct ata_device *dev) { return 0; }
 #endif
 
-- 
2.51.0

Re: [PATCH v5 3/3] ata: Use ACPI methods to power on disks

[Damien Le Moal]

On 10/28/25 5:23 AM, Markus Probst wrote:
> Some embedded devices have the ability to control whether power is
> provided to the disks via the SATA power connector or not. If power
> resources are defined on ATA ports / devices in ACPI, we should try to set
> the power state to D0 before probing the disk to ensure that any power
> supply or power gate that may exist is providing power to the disk.
> 
> An example for such devices would be newer synology NAS devices. Every
> disk slot has its own SATA power connector. Whether the connector is
> providing power is controlled via an gpio, which is *off by default*.
> Also the disk loses power on reboots.
> 
> Add a new function, ata_acpi_port_power_on(), that will be used to power
> on the SATA power connector if usable ACPI power resources on the
> associated ATA port / device are found. It will be called right before
> probing the port, therefore the disk will be powered on just in time.
> 
> Signed-off-by: Markus Probst <markus.probst@posteo.de>

I think that this patch should be 2/3 and 2/3 should be 3/3. That makes more
sense to have the basic power control first and then solve the restart power
loss after that.

> ---
>  drivers/ata/libata-acpi.c | 40 +++++++++++++++++++++++++++++++++++++++
>  drivers/ata/libata-core.c |  2 ++
>  drivers/ata/libata.h      |  2 ++
>  3 files changed, 44 insertions(+)
> 
> diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
> index 196ca1227d09..b0d70e075cd2 100644
> --- a/drivers/ata/libata-acpi.c
> +++ b/drivers/ata/libata-acpi.c
> @@ -271,6 +271,46 @@ bool ata_acpi_dev_manage_restart(struct ata_device *dev)
>  	return acpi_bus_power_manageable(ACPI_HANDLE(tdev));
>  }
>  
> +/**
> + * ata_acpi_port_power_on - set the power state of the ata port to D0
> + * @ap: target ATA port
> + *
> + * This function is called at the beginning of ata_port_probe.

Please add "()" after ata_port_probe ("ata_port_probe()") to show it is a function.

> + */
> +void ata_acpi_port_power_on(struct ata_port *ap)
> +{
> +	acpi_handle handle;
> +	int i;
> +
> +	/* If `ATA_FLAG_ACPI_SATA` is set, the acpi fwnode is attached to the
> +	 * `ata_device` instead of the `ata_port`.
> +	 */

As already commented, please drop the quote marks inside the comment (not
needed at all) and format the multi line comment correctly:

	/*
	 * If ATA_FLAG_ACPI_SATA is set, the acpi fwnode is attached to the
	 * ATA device instead of the ATA port.
	 */

> +	if (ap->flags & ATA_FLAG_ACPI_SATA) {
> +		for (i = 0; i < ATA_MAX_DEVICES; i++) {
> +			struct ata_device *dev = &ap->link.device[i];
> +
> +			if (!is_acpi_device_node(dev->tdev.fwnode))
> +				continue;
> +			handle = ACPI_HANDLE(&dev->tdev);
> +			if (!acpi_bus_power_manageable(handle))
> +				continue;
> +			if (acpi_bus_set_power(handle, ACPI_STATE_D0))
> +				ata_dev_err(dev,
> +					    "acpi: failed to power state to D0\n");

"acpi: failed to set power state to D0\n" ? (set missing ?)

> +		}
> +		return;
> +	}
> +
> +	if (!is_acpi_device_node(ap->tdev.fwnode))
> +		return;
> +	handle = ACPI_HANDLE(&ap->tdev);
> +	if (!acpi_bus_power_manageable(handle))
> +		return;
> +
> +	if (acpi_bus_set_power(handle, ACPI_STATE_D0))
> +		ata_port_err(ap, "acpi: failed to set power state to D0\n");

Not missing here :)

> +}
> +
>  /**
>   * ata_acpi_dissociate - dissociate ATA host from ACPI objects
>   * @host: target ATA host
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 2a210719c4ce..a6813ced3ec2 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5901,6 +5901,8 @@ void ata_port_probe(struct ata_port *ap)
>  	struct ata_eh_info *ehi = &ap->link.eh_info;
>  	unsigned long flags;
>  
> +	ata_acpi_port_power_on(ap);
> +
>  	/* kick EH for boot probing */
>  	spin_lock_irqsave(ap->lock, flags);
>  
> diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
> index af08bb9b40d0..0e7ecac73680 100644
> --- a/drivers/ata/libata.h
> +++ b/drivers/ata/libata.h
> @@ -130,6 +130,7 @@ extern void ata_acpi_on_disable(struct ata_device *dev);
>  extern void ata_acpi_set_state(struct ata_port *ap, pm_message_t state);
>  extern void ata_acpi_bind_port(struct ata_port *ap);
>  extern void ata_acpi_bind_dev(struct ata_device *dev);
> +extern void ata_acpi_port_power_on(struct ata_port *ap);
>  extern bool ata_acpi_dev_manage_restart(struct ata_device *dev);
>  extern acpi_handle ata_dev_acpi_handle(struct ata_device *dev);
>  #else
> @@ -141,6 +142,7 @@ static inline void ata_acpi_set_state(struct ata_port *ap,
>  				      pm_message_t state) { }
>  static inline void ata_acpi_bind_port(struct ata_port *ap) {}
>  static inline void ata_acpi_bind_dev(struct ata_device *dev) {}
> +static inline void ata_acpi_port_power_on(struct ata_port *ap) {}
>  static inline bool ata_acpi_dev_manage_restart(struct ata_device *dev) { return 0; }
>  #endif
>  


-- 
Damien Le Moal
Western Digital Research