Merge tag 'ata-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata

Pull ATA fixes from Damien Le Moal:
 "A larger than usual set of fixes for 6.6-rc4 due to the unexpected
  number of fixes needed to address ATA disks suspend/resume issues.

  In more detail:

   - Add missing additionalProperties on child nodes to the pata-common
     DT bindings (Rob)

   - Fix handling of the REPORT SUPPORTED OPERATION CODES command to
     ignore reserved bits (Niklas)

   - Increase port multiplier soft reset timeout to accomodate slow
     devices and avoid issues on wakeup (Matthias)

   - A couple of minor code fixes to avoid compilation warnings in
     libata-core and libata-eh (me)

   - Many patches from me to address suspend/resume issues, and in
     particular a potential deadlock on resume due to the SCSI disk
     driver resume operation not being synchronized with libata EH port
     resume handling.

     This is addressed by changing the scsi disk driver disk start/stop
     control to allow libata to execute disk suspend (spin down) and
     resume (spin up) on its own during system suspend/resume. Runtime
     suspend/resume control remains with the SCSI disk driver.

     Other fixes include:
      - Fix libata power management request issuing to avoid races
      - Establish a link between ATA ports and SCSI devices to order PM
        operations
      - Fix device removal to avoid issues with driver rmmod removal
      - Fix synchronization of libata device rescan and SCSI disk resume
        operation
      - Remove libsas PM operations as suspend/resume is handled
        directly by the sas controller resume
      - Fix the SCSI disk driver to not issue commands to suspended
        disks, thus avoiding potential system lock-up on resume"

* tag 'ata-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-eh: Fix compilation warning in ata_eh_link_report()
  ata: libata-core: Fix compilation warning in ata_dev_config_ncq()
  scsi: sd: Do not issue commands to suspended disks on shutdown
  ata: libata-core: Do not register PM operations for SAS ports
  ata: libata-scsi: Fix delayed scsi_rescan_device() execution
  scsi: Do not attempt to rescan suspended devices
  ata: libata-scsi: Disable scsi device manage_system_start_stop
  scsi: sd: Differentiate system and runtime start/stop management
  ata: libata-scsi: link ata port and scsi device
  ata: libata-core: Fix port and device removal
  ata: libata-core: Fix ata_port_request_pm() locking
  ata: libata-sata: increase PMP SRST timeout to 10s
  ata: libata-scsi: ignore reserved bits for REPORT SUPPORTED OPERATION CODES
  dt-bindings: ata: pata-common: Add missing additionalProperties on child nodes

Documentation/devicetree/bindings/ata/pata-common.yaml

@@ -38,6 +38,7 @@ patternProperties:
       ID number 0 and the slave drive will have ID number 1. The PATA port
       nodes will be named "ide-port".
     type: object
+    additionalProperties: false
 
     properties:
       reg:

drivers/ata/libata-core.c

@@ -1972,6 +1972,96 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
 	return rc;
 }
 
+/**
+ *	ata_dev_power_set_standby - Set a device power mode to standby
+ *	@dev: target device
+ *
+ *	Issue a STANDBY IMMEDIATE command to set a device power mode to standby.
+ *	For an HDD device, this spins down the disks.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+void ata_dev_power_set_standby(struct ata_device *dev)
+{
+	unsigned long ap_flags = dev->link->ap->flags;
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	/* Issue STANDBY IMMEDIATE command only if supported by the device */
+	if (dev->class != ATA_DEV_ATA && dev->class != ATA_DEV_ZAC)
+		return;
+
+	/*
+	 * Some odd clown BIOSes issue spindown on power off (ACPI S4 or S5)
+	 * causing some drives to spin up and down again. For these, do nothing
+	 * if we are being called on shutdown.
+	 */
+	if ((ap_flags & ATA_FLAG_NO_POWEROFF_SPINDOWN) &&
+	    system_state == SYSTEM_POWER_OFF)
+		return;
+
+	if ((ap_flags & ATA_FLAG_NO_HIBERNATE_SPINDOWN) &&
+	    system_entering_hibernation())
+		return;
+
+	ata_tf_init(dev, &tf);
+	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+	tf.protocol = ATA_PROT_NODATA;
+	tf.command = ATA_CMD_STANDBYNOW1;
+
+	ata_dev_notice(dev, "Entering standby power mode\n");
+
+	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+	if (err_mask)
+		ata_dev_err(dev, "STANDBY IMMEDIATE failed (err_mask=0x%x)\n",
+			    err_mask);
+}
+
+/**
+ *	ata_dev_power_set_active -  Set a device power mode to active
+ *	@dev: target device
+ *
+ *	Issue a VERIFY command to enter to ensure that the device is in the
+ *	active power mode. For a spun-down HDD (standby or idle power mode),
+ *	the VERIFY command will complete after the disk spins up.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+void ata_dev_power_set_active(struct ata_device *dev)
+{
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	/*
+	 * Issue READ VERIFY SECTORS command for 1 sector at lba=0 only
+	 * if supported by the device.
+	 */
+	if (dev->class != ATA_DEV_ATA && dev->class != ATA_DEV_ZAC)
+		return;
+
+	ata_tf_init(dev, &tf);
+	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+	tf.protocol = ATA_PROT_NODATA;
+	tf.command = ATA_CMD_VERIFY;
+	tf.nsect = 1;
+	if (dev->flags & ATA_DFLAG_LBA) {
+		tf.flags |= ATA_TFLAG_LBA;
+		tf.device |= ATA_LBA;
+	} else {
+		/* CHS */
+		tf.lbal = 0x1; /* sect */
+	}
+
+	ata_dev_notice(dev, "Entering active power mode\n");
+
+	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+	if (err_mask)
+		ata_dev_err(dev, "VERIFY failed (err_mask=0x%x)\n",
+			    err_mask);
+}
+
 /**
  *	ata_read_log_page - read a specific log page
  *	@dev: target device
@@ -2529,7 +2619,7 @@ static int ata_dev_config_lba(struct ata_device *dev)
 {
 	const u16 *id = dev->id;
 	const char *lba_desc;
-	char ncq_desc[24];
+	char ncq_desc[32];
 	int ret;
 
 	dev->flags |= ATA_DFLAG_LBA;
@@ -5037,17 +5127,19 @@ static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
 	struct ata_link *link;
 	unsigned long flags;
 
-	/* Previous resume operation might still be in
-	 * progress.  Wait for PM_PENDING to clear.
+	spin_lock_irqsave(ap->lock, flags);
+
+	/*
+	 * A previous PM operation might still be in progress. Wait for
+	 * ATA_PFLAG_PM_PENDING to clear.
 	 */
 	if (ap->pflags & ATA_PFLAG_PM_PENDING) {
+		spin_unlock_irqrestore(ap->lock, flags);
 		ata_port_wait_eh(ap);
-		WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
-	}
-
-	/* request PM ops to EH */
 		spin_lock_irqsave(ap->lock, flags);
+	}
 
+	/* Request PM operation to EH */
 	ap->pm_mesg = mesg;
 	ap->pflags |= ATA_PFLAG_PM_PENDING;
 	ata_for_each_link(link, ap, HOST_FIRST) {
@@ -5059,10 +5151,8 @@ static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
 
 	spin_unlock_irqrestore(ap->lock, flags);
 
-	if (!async) {
+	if (!async)
 		ata_port_wait_eh(ap);
-		WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
-	}
 }
 
 /*
@@ -5078,11 +5168,27 @@ static const unsigned int ata_port_suspend_ehi = ATA_EHI_QUIET
 
 static void ata_port_suspend(struct ata_port *ap, pm_message_t mesg)
 {
+	/*
+	 * We are about to suspend the port, so we do not care about
+	 * scsi_rescan_device() calls scheduled by previous resume operations.
+	 * The next resume will schedule the rescan again. So cancel any rescan
+	 * that is not done yet.
+	 */
+	cancel_delayed_work_sync(&ap->scsi_rescan_task);
+
 	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, false);
 }
 
 static void ata_port_suspend_async(struct ata_port *ap, pm_message_t mesg)
 {
+	/*
+	 * We are about to suspend the port, so we do not care about
+	 * scsi_rescan_device() calls scheduled by previous resume operations.
+	 * The next resume will schedule the rescan again. So cancel any rescan
+	 * that is not done yet.
+	 */
+	cancel_delayed_work_sync(&ap->scsi_rescan_task);
+
 	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, true);
 }
 
@@ -5229,7 +5335,7 @@ EXPORT_SYMBOL_GPL(ata_host_resume);
 #endif
 
 const struct device_type ata_port_type = {
-	.name = "ata_port",
+	.name = ATA_PORT_TYPE_NAME,
 #ifdef CONFIG_PM
 	.pm = &ata_port_pm_ops,
 #endif
@@ -5948,11 +6054,30 @@ static void ata_port_detach(struct ata_port *ap)
 	struct ata_link *link;
 	struct ata_device *dev;
 
-	/* tell EH we're leaving & flush EH */
+	/* Wait for any ongoing EH */
+	ata_port_wait_eh(ap);
+
+	mutex_lock(&ap->scsi_scan_mutex);
 	spin_lock_irqsave(ap->lock, flags);
+
+	/* Remove scsi devices */
+	ata_for_each_link(link, ap, HOST_FIRST) {
+		ata_for_each_dev(dev, link, ALL) {
+			if (dev->sdev) {
+				spin_unlock_irqrestore(ap->lock, flags);
+				scsi_remove_device(dev->sdev);
+				spin_lock_irqsave(ap->lock, flags);
+				dev->sdev = NULL;
+			}
+		}
+	}
+
+	/* Tell EH to disable all devices */
 	ap->pflags |= ATA_PFLAG_UNLOADING;
 	ata_port_schedule_eh(ap);
+
 	spin_unlock_irqrestore(ap->lock, flags);
+	mutex_unlock(&ap->scsi_scan_mutex);
 
 	/* wait till EH commits suicide */
 	ata_port_wait_eh(ap);

drivers/ata/libata-eh.c

@@ -147,6 +147,8 @@ ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
 	  .timeouts = ata_eh_other_timeouts, },
 	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
 	  .timeouts = ata_eh_flush_timeouts },
+	{ .commands = CMDS(ATA_CMD_VERIFY),
+	  .timeouts = ata_eh_reset_timeouts },
 };
 #undef CMDS
 
@@ -498,7 +500,19 @@ static void ata_eh_unload(struct ata_port *ap)
 	struct ata_device *dev;
 	unsigned long flags;
 
-	/* Restore SControl IPM and SPD for the next driver and
+	/*
+	 * Unless we are restarting, transition all enabled devices to
+	 * standby power mode.
+	 */
+	if (system_state != SYSTEM_RESTART) {
+		ata_for_each_link(link, ap, PMP_FIRST) {
+			ata_for_each_dev(dev, link, ENABLED)
+				ata_dev_power_set_standby(dev);
+		}
+	}
+
+	/*
+	 * Restore SControl IPM and SPD for the next driver and
 	 * disable attached devices.
 	 */
 	ata_for_each_link(link, ap, PMP_FIRST) {
@@ -684,6 +698,10 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
 			ehc->saved_xfer_mode[devno] = dev->xfer_mode;
 			if (ata_ncq_enabled(dev))
 				ehc->saved_ncq_enabled |= 1 << devno;
+
+			/* If we are resuming, wake up the device */
+			if (ap->pflags & ATA_PFLAG_RESUMING)
+				ehc->i.dev_action[devno] |= ATA_EH_SET_ACTIVE;
 		}
 	}
 
@@ -743,6 +761,8 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
 	/* clean up */
 	spin_lock_irqsave(ap->lock, flags);
 
+	ap->pflags &= ~ATA_PFLAG_RESUMING;
+
 	if (ap->pflags & ATA_PFLAG_LOADING)
 		ap->pflags &= ~ATA_PFLAG_LOADING;
 	else if ((ap->pflags & ATA_PFLAG_SCSI_HOTPLUG) &&
@@ -1218,6 +1238,13 @@ void ata_eh_detach_dev(struct ata_device *dev)
 	struct ata_eh_context *ehc = &link->eh_context;
 	unsigned long flags;
 
+	/*
+	 * If the device is still enabled, transition it to standby power mode
+	 * (i.e. spin down HDDs).
+	 */
+	if (ata_dev_enabled(dev))
+		ata_dev_power_set_standby(dev);
+
 	ata_dev_disable(dev);
 
 	spin_lock_irqsave(ap->lock, flags);
@@ -2305,7 +2332,7 @@ static void ata_eh_link_report(struct ata_link *link)
 	struct ata_eh_context *ehc = &link->eh_context;
 	struct ata_queued_cmd *qc;
 	const char *frozen, *desc;
-	char tries_buf[6] = "";
+	char tries_buf[16] = "";
 	int tag, nr_failed = 0;
 
 	if (ehc->i.flags & ATA_EHI_QUIET)
@@ -3016,6 +3043,15 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 		if (ehc->i.flags & ATA_EHI_DID_RESET)
 			readid_flags |= ATA_READID_POSTRESET;
 
+		/*
+		 * When resuming, before executing any command, make sure to
+		 * transition the device to the active power mode.
+		 */
+		if ((action & ATA_EH_SET_ACTIVE) && ata_dev_enabled(dev)) {
+			ata_dev_power_set_active(dev);
+			ata_eh_done(link, dev, ATA_EH_SET_ACTIVE);
+		}
+
 		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
 			WARN_ON(dev->class == ATA_DEV_PMP);
 
@@ -3989,6 +4025,7 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap)
 	unsigned long flags;
 	int rc = 0;
 	struct ata_device *dev;
+	struct ata_link *link;
 
 	/* are we suspending? */
 	spin_lock_irqsave(ap->lock, flags);
@@ -4001,6 +4038,12 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap)
 
 	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
 
+	/* Set all devices attached to the port in standby mode */
+	ata_for_each_link(link, ap, HOST_FIRST) {
+		ata_for_each_dev(dev, link, ENABLED)
+			ata_dev_power_set_standby(dev);
+	}
+
 	/*
 	 * If we have a ZPODD attached, check its zero
 	 * power ready status before the port is frozen.
@@ -4083,6 +4126,7 @@ static void ata_eh_handle_port_resume(struct ata_port *ap)
 	/* update the flags */
 	spin_lock_irqsave(ap->lock, flags);
 	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
+	ap->pflags |= ATA_PFLAG_RESUMING;
 	spin_unlock_irqrestore(ap->lock, flags);
 }
 #endif /* CONFIG_PM */

drivers/ata/libata-scsi.c

@@ -1050,14 +1050,13 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
 		}
 	} else {
 		sdev->sector_size = ata_id_logical_sector_size(dev->id);
+
 		/*
-		 * Stop the drive on suspend but do not issue START STOP UNIT
-		 * on resume as this is not necessary and may fail: the device
-		 * will be woken up by ata_port_pm_resume() with a port reset
-		 * and device revalidation.
+		 * Ask the sd driver to issue START STOP UNIT on runtime suspend
+		 * and resume only. For system level suspend/resume, devices
+		 * power state is handled directly by libata EH.
 		 */
-		sdev->manage_start_stop = 1;
-		sdev->no_start_on_resume = 1;
+		sdev->manage_runtime_start_stop = true;
 	}
 
 	/*
@@ -1089,6 +1088,42 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
 	return 0;
 }
 
+/**
+ *	ata_scsi_slave_alloc - Early setup of SCSI device
+ *	@sdev: SCSI device to examine
+ *
+ *	This is called from scsi_alloc_sdev() when the scsi device
+ *	associated with an ATA device is scanned on a port.
+ *
+ *	LOCKING:
+ *	Defined by SCSI layer.  We don't really care.
+ */
+
+int ata_scsi_slave_alloc(struct scsi_device *sdev)
+{
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct device_link *link;
+
+	ata_scsi_sdev_config(sdev);
+
+	/*
+	 * Create a link from the ata_port device to the scsi device to ensure
+	 * that PM does suspend/resume in the correct order: the scsi device is
+	 * consumer (child) and the ata port the supplier (parent).
+	 */
+	link = device_link_add(&sdev->sdev_gendev, &ap->tdev,
+			       DL_FLAG_STATELESS |
+			       DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE);
+	if (!link) {
+		ata_port_err(ap, "Failed to create link to scsi device %s\n",
+			     dev_name(&sdev->sdev_gendev));
+		return -ENODEV;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_scsi_slave_alloc);
+
 /**
  *	ata_scsi_slave_config - Set SCSI device attributes
  *	@sdev: SCSI device to examine
@@ -1105,14 +1140,11 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 {
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
-	int rc = 0;
-
-	ata_scsi_sdev_config(sdev);
 
 	if (dev)
-		rc = ata_scsi_dev_config(sdev, dev);
+		return ata_scsi_dev_config(sdev, dev);
 
-	return rc;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
 
@@ -1136,6 +1168,8 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
 	unsigned long flags;
 	struct ata_device *dev;
 
+	device_link_remove(&sdev->sdev_gendev, &ap->tdev);
+
 	spin_lock_irqsave(ap->lock, flags);
 	dev = __ata_scsi_find_dev(ap, sdev);
 	if (dev && dev->sdev) {
@@ -4315,7 +4349,7 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
 		break;
 
 	case MAINTENANCE_IN:
-		if (scsicmd[1] == MI_REPORT_SUPPORTED_OPERATION_CODES)
+		if ((scsicmd[1] & 0x1f) == MI_REPORT_SUPPORTED_OPERATION_CODES)
 			ata_scsi_rbuf_fill(&args, ata_scsiop_maint_in);
 		else
 			ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
@@ -4725,7 +4759,7 @@ void ata_scsi_dev_rescan(struct work_struct *work)
 	struct ata_link *link;
 	struct ata_device *dev;
 	unsigned long flags;
-	bool delay_rescan = false;
+	int ret = 0;
 
 	mutex_lock(&ap->scsi_scan_mutex);
 	spin_lock_irqsave(ap->lock, flags);
@@ -4734,37 +4768,34 @@ void ata_scsi_dev_rescan(struct work_struct *work)
 		ata_for_each_dev(dev, link, ENABLED) {
 			struct scsi_device *sdev = dev->sdev;
 
+			/*
+			 * If the port was suspended before this was scheduled,
+			 * bail out.
+			 */
+			if (ap->pflags & ATA_PFLAG_SUSPENDED)
+				goto unlock;
+
 			if (!sdev)
 				continue;
 			if (scsi_device_get(sdev))
 				continue;
 
-			/*
-			 * If the rescan work was scheduled because of a resume
-			 * event, the port is already fully resumed, but the
-			 * SCSI device may not yet be fully resumed. In such
-			 * case, executing scsi_rescan_device() may cause a
-			 * deadlock with the PM code on device_lock(). Prevent
-			 * this by giving up and retrying rescan after a short
-			 * delay.
-			 */
-			delay_rescan = sdev->sdev_gendev.power.is_suspended;
-			if (delay_rescan) {
-				scsi_device_put(sdev);
-				break;
-			}
-
 			spin_unlock_irqrestore(ap->lock, flags);
-			scsi_rescan_device(sdev);
+			ret = scsi_rescan_device(sdev);
 			scsi_device_put(sdev);
 			spin_lock_irqsave(ap->lock, flags);
+
+			if (ret)
+				goto unlock;
 		}
 	}
 
+unlock:
 	spin_unlock_irqrestore(ap->lock, flags);
 	mutex_unlock(&ap->scsi_scan_mutex);
 
-	if (delay_rescan)
+	/* Reschedule with a delay if scsi_rescan_device() returned an error */
+	if (ret)
 		schedule_delayed_work(&ap->scsi_rescan_task,
 				      msecs_to_jiffies(5));
 }

drivers/ata/libata-transport.c

@@ -266,6 +266,10 @@ void ata_tport_delete(struct ata_port *ap)
 	put_device(dev);
 }
 
+static const struct device_type ata_port_sas_type = {
+	.name = ATA_PORT_TYPE_NAME,
+};
+
 /** ata_tport_add - initialize a transport ATA port structure
  *
  * @parent:	parent device
@@ -283,6 +287,9 @@ int ata_tport_add(struct device *parent,
 	struct device *dev = &ap->tdev;
 
 	device_initialize(dev);
+	if (ap->flags & ATA_FLAG_SAS_HOST)
+		dev->type = &ata_port_sas_type;
+	else
 		dev->type = &ata_port_type;
 
 	dev->parent = parent;

drivers/ata/libata.h

@@ -30,6 +30,8 @@ enum {
 	ATA_DNXFER_QUIET	= (1 << 31),
 };
 
+#define ATA_PORT_TYPE_NAME	"ata_port"
+
 extern atomic_t ata_print_id;
 extern int atapi_passthru16;
 extern int libata_fua;
@@ -60,6 +62,8 @@ extern int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags);
 extern int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
 			      unsigned int readid_flags);
 extern int ata_dev_configure(struct ata_device *dev);
+extern void ata_dev_power_set_standby(struct ata_device *dev);
+extern void ata_dev_power_set_active(struct ata_device *dev);
 extern int sata_down_spd_limit(struct ata_link *link, u32 spd_limit);
 extern int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel);
 extern unsigned int ata_dev_set_feature(struct ata_device *dev,

drivers/firewire/sbp2.c

@@ -81,7 +81,8 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  *
  * - power condition
  *   Set the power condition field in the START STOP UNIT commands sent by
- *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
+ *   sd_mod on suspend, resume, and shutdown (if manage_system_start_stop or
+ *   manage_runtime_start_stop is on).
  *   Some disks need this to spin down or to resume properly.
  *
  * - override internal blacklist
@@ -1517,8 +1518,10 @@ static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
 
 	sdev->use_10_for_rw = 1;
 
-	if (sbp2_param_exclusive_login)
-		sdev->manage_start_stop = 1;
+	if (sbp2_param_exclusive_login) {
+		sdev->manage_system_start_stop = true;
+		sdev->manage_runtime_start_stop = true;
+	}
 
 	if (sdev->type == TYPE_ROM)
 		sdev->use_10_for_ms = 1;

drivers/scsi/scsi_scan.c

@@ -1619,12 +1619,24 @@ int scsi_add_device(struct Scsi_Host *host, uint channel,
 }
 EXPORT_SYMBOL(scsi_add_device);
 
-void scsi_rescan_device(struct scsi_device *sdev)
+int scsi_rescan_device(struct scsi_device *sdev)
 {
 	struct device *dev = &sdev->sdev_gendev;
+	int ret = 0;
 
 	device_lock(dev);
 
+	/*
+	 * Bail out if the device is not running. Otherwise, the rescan may
+	 * block waiting for commands to be executed, with us holding the
+	 * device lock. This can result in a potential deadlock in the power
+	 * management core code when system resume is on-going.
+	 */
+	if (sdev->sdev_state != SDEV_RUNNING) {
+		ret = -EWOULDBLOCK;
+		goto unlock;
+	}
+
 	scsi_attach_vpd(sdev);
 	scsi_cdl_check(sdev);
 
@@ -1638,7 +1650,11 @@ void scsi_rescan_device(struct scsi_device *sdev)
 			drv->rescan(dev);
 		module_put(dev->driver->owner);
 	}
+
+unlock:
 	device_unlock(dev);
+
+	return ret;
 }
 EXPORT_SYMBOL(scsi_rescan_device);
 

drivers/scsi/sd.c

@@ -201,17 +201,62 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 }
 
 static ssize_t
-manage_start_stop_show(struct device *dev, struct device_attribute *attr,
-		       char *buf)
+manage_start_stop_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_system_start_stop &&
+			  sdp->manage_runtime_start_stop);
+}
+static DEVICE_ATTR_RO(manage_start_stop);
+
+static ssize_t
+manage_system_start_stop_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_system_start_stop);
+}
+
+static ssize_t
+manage_system_start_stop_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_system_start_stop = v;
+
+	return count;
+}
+static DEVICE_ATTR_RW(manage_system_start_stop);
+
+static ssize_t
+manage_runtime_start_stop_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 sprintf(buf, "%u\n", sdp->manage_start_stop);
+	return sysfs_emit(buf, "%u\n", sdp->manage_runtime_start_stop);
 }
 
 static ssize_t
-manage_start_stop_store(struct device *dev, struct device_attribute *attr,
+manage_runtime_start_stop_store(struct device *dev,
+				struct device_attribute *attr,
 				const char *buf, size_t count)
 {
 	struct scsi_disk *sdkp = to_scsi_disk(dev);
@@ -224,11 +269,11 @@ manage_start_stop_store(struct device *dev, struct device_attribute *attr,
 	if (kstrtobool(buf, &v))
 		return -EINVAL;
 
-	sdp->manage_start_stop = v;
+	sdp->manage_runtime_start_stop = v;
 
 	return count;
 }
-static DEVICE_ATTR_RW(manage_start_stop);
+static DEVICE_ATTR_RW(manage_runtime_start_stop);
 
 static ssize_t
 allow_restart_show(struct device *dev, struct device_attribute *attr, char *buf)
@@ -560,6 +605,8 @@ static struct attribute *sd_disk_attrs[] = {
 	&dev_attr_FUA.attr,
 	&dev_attr_allow_restart.attr,
 	&dev_attr_manage_start_stop.attr,
+	&dev_attr_manage_system_start_stop.attr,
+	&dev_attr_manage_runtime_start_stop.attr,
 	&dev_attr_protection_type.attr,
 	&dev_attr_protection_mode.attr,
 	&dev_attr_app_tag_own.attr,
@@ -3694,6 +3741,7 @@ static int sd_remove(struct device *dev)
 
 	device_del(&sdkp->disk_dev);
 	del_gendisk(sdkp->disk);
+	if (!sdkp->suspended)
 		sd_shutdown(dev);
 
 	put_disk(sdkp->disk);
@@ -3771,13 +3819,20 @@ static void sd_shutdown(struct device *dev)
 		sd_sync_cache(sdkp, NULL);
 	}
 
-	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
+	if (system_state != SYSTEM_RESTART &&
+	    sdkp->device->manage_system_start_stop) {
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		sd_start_stop_device(sdkp, 0);
 	}
 }
 
-static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
+static inline bool sd_do_start_stop(struct scsi_device *sdev, bool runtime)
+{
+	return (sdev->manage_system_start_stop && !runtime) ||
+		(sdev->manage_runtime_start_stop && runtime);
+}
+
+static int sd_suspend_common(struct device *dev, bool runtime)
 {
 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
 	struct scsi_sense_hdr sshdr;
@@ -3809,15 +3864,18 @@ static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
 		}
 	}
 
-	if (sdkp->device->manage_start_stop) {
+	if (sd_do_start_stop(sdkp->device, runtime)) {
 		if (!sdkp->device->silence_suspend)
 			sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		/* an error is not worth aborting a system sleep */
 		ret = sd_start_stop_device(sdkp, 0);
-		if (ignore_stop_errors)
+		if (!runtime)
 			ret = 0;
 	}
 
+	if (!ret)
+		sdkp->suspended = true;
+
 	return ret;
 }
 
@@ -3826,15 +3884,15 @@ static int sd_suspend_system(struct device *dev)
 	if (pm_runtime_suspended(dev))
 		return 0;
 
-	return sd_suspend_common(dev, true);
+	return sd_suspend_common(dev, false);
 }
 
 static int sd_suspend_runtime(struct device *dev)
 {
-	return sd_suspend_common(dev, false);
+	return sd_suspend_common(dev, true);
 }
 
-static int sd_resume(struct device *dev)
+static int sd_resume(struct device *dev, bool runtime)
 {
 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
 	int ret = 0;
@@ -3842,16 +3900,21 @@ static int sd_resume(struct device *dev)
 	if (!sdkp)	/* E.g.: runtime resume at the start of sd_probe() */
 		return 0;
 
-	if (!sdkp->device->manage_start_stop)
+	if (!sd_do_start_stop(sdkp->device, runtime)) {
+		sdkp->suspended = false;
 		return 0;
+	}
 
 	if (!sdkp->device->no_start_on_resume) {
 		sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
 		ret = sd_start_stop_device(sdkp, 1);
 	}
 
-	if (!ret)
+	if (!ret) {
 		opal_unlock_from_suspend(sdkp->opal_dev);
+		sdkp->suspended = false;
+	}
+
 	return ret;
 }
 
@@ -3860,7 +3923,7 @@ static int sd_resume_system(struct device *dev)
 	if (pm_runtime_suspended(dev))
 		return 0;
 
-	return sd_resume(dev);
+	return sd_resume(dev, false);
 }
 
 static int sd_resume_runtime(struct device *dev)
@@ -3887,7 +3950,7 @@ static int sd_resume_runtime(struct device *dev)
 				  "Failed to clear sense data\n");
 	}
 
-	return sd_resume(dev);
+	return sd_resume(dev, true);
 }
 
 static const struct dev_pm_ops sd_pm_ops = {

drivers/scsi/sd.h

@@ -131,6 +131,7 @@ struct scsi_disk {
 	u8		provisioning_mode;
 	u8		zeroing_mode;
 	u8		nr_actuators;		/* Number of actuators */
+	bool		suspended;	/* Disk is suspended (stopped) */
 	unsigned	ATO : 1;	/* state of disk ATO bit */
 	unsigned	cache_override : 1; /* temp override of WCE,RCD */
 	unsigned	WCE : 1;	/* state of disk WCE bit */

include/linux/libata.h

@@ -192,6 +192,7 @@ enum {
 	ATA_PFLAG_UNLOADING	= (1 << 9), /* driver is being unloaded */
 	ATA_PFLAG_UNLOADED	= (1 << 10), /* driver is unloaded */
 
+	ATA_PFLAG_RESUMING	= (1 << 16),  /* port is being resumed */
 	ATA_PFLAG_SUSPENDED	= (1 << 17), /* port is suspended (power) */
 	ATA_PFLAG_PM_PENDING	= (1 << 18), /* PM operation pending */
 	ATA_PFLAG_INIT_GTM_VALID = (1 << 19), /* initial gtm data valid */
@@ -259,7 +260,7 @@ enum {
 	 * advised to wait only for the following duration before
 	 * doing SRST.
 	 */
-	ATA_TMOUT_PMP_SRST_WAIT	= 5000,
+	ATA_TMOUT_PMP_SRST_WAIT	= 10000,
 
 	/* When the LPM policy is set to ATA_LPM_MAX_POWER, there might
 	 * be a spurious PHY event, so ignore the first PHY event that
@@ -318,9 +319,10 @@ enum {
 	ATA_EH_ENABLE_LINK	= (1 << 3),
 	ATA_EH_PARK		= (1 << 5), /* unload heads and stop I/O */
 	ATA_EH_GET_SUCCESS_SENSE = (1 << 6), /* Get sense data for successful cmd */
+	ATA_EH_SET_ACTIVE	= (1 << 7), /* Set a device to active power mode */
 
 	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE | ATA_EH_PARK |
-				  ATA_EH_GET_SUCCESS_SENSE,
+				  ATA_EH_GET_SUCCESS_SENSE | ATA_EH_SET_ACTIVE,
 	ATA_EH_ALL_ACTIONS	= ATA_EH_REVALIDATE | ATA_EH_RESET |
 				  ATA_EH_ENABLE_LINK,
 
@@ -357,7 +359,7 @@ enum {
 	/* This should match the actual table size of
 	 * ata_eh_cmd_timeout_table in libata-eh.c.
 	 */
-	ATA_EH_CMD_TIMEOUT_TABLE_SIZE = 7,
+	ATA_EH_CMD_TIMEOUT_TABLE_SIZE = 8,
 
 	/* Horkage types. May be set by libata or controller on drives
 	   (some horkage may be drive/controller pair dependent */
@@ -1148,6 +1150,7 @@ extern int ata_std_bios_param(struct scsi_device *sdev,
 			      struct block_device *bdev,
 			      sector_t capacity, int geom[]);
 extern void ata_scsi_unlock_native_capacity(struct scsi_device *sdev);
+extern int ata_scsi_slave_alloc(struct scsi_device *sdev);
 extern int ata_scsi_slave_config(struct scsi_device *sdev);
 extern void ata_scsi_slave_destroy(struct scsi_device *sdev);
 extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
@@ -1396,6 +1399,7 @@ extern const struct attribute_group *ata_common_sdev_groups[];
 	.this_id		= ATA_SHT_THIS_ID,		\
 	.emulated		= ATA_SHT_EMULATED,		\
 	.proc_name		= drv_name,			\
+	.slave_alloc		= ata_scsi_slave_alloc,		\
 	.slave_destroy		= ata_scsi_slave_destroy,	\
 	.bios_param		= ata_std_bios_param,		\
 	.unlock_native_capacity	= ata_scsi_unlock_native_capacity,\

include/scsi/scsi_device.h

@@ -161,6 +161,10 @@ struct scsi_device {
 				 * pass settings from slave_alloc to scsi
 				 * core. */
 	unsigned int eh_timeout; /* Error handling timeout */
+
+	bool manage_system_start_stop; /* Let HLD (sd) manage system start/stop */
+	bool manage_runtime_start_stop; /* Let HLD (sd) manage runtime start/stop */
+
 	unsigned removable:1;
 	unsigned changed:1;	/* Data invalid due to media change */
 	unsigned busy:1;	/* Used to prevent races */
@@ -193,7 +197,6 @@ struct scsi_device {
 	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
 	unsigned no_start_on_add:1;	/* do not issue start on add */
 	unsigned allow_restart:1; /* issue START_UNIT in error handler */
-	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */
 	unsigned no_start_on_resume:1; /* Do not issue START_STOP_UNIT on resume */
 	unsigned start_stop_pwr_cond:1;	/* Set power cond. in START_STOP_UNIT */
 	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */

include/scsi/scsi_host.h

@@ -764,7 +764,7 @@ scsi_template_proc_dir(const struct scsi_host_template *sht);
 #define scsi_template_proc_dir(sht) NULL
 #endif
 extern void scsi_scan_host(struct Scsi_Host *);
-extern void scsi_rescan_device(struct scsi_device *);
+extern int scsi_rescan_device(struct scsi_device *sdev);
 extern void scsi_remove_host(struct Scsi_Host *);
 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
 extern int scsi_host_busy(struct Scsi_Host *shost);