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

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index eaa972bee6c0..902655d75947 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/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);