scsi: sd: Fix system start for ATA devices

commit b09d7f8fd50f6e93cbadd8d27fde178f745b42a1 upstream.

It is not always possible to keep a device in the runtime suspended state
when a system level suspend/resume cycle is executed. E.g. for ATA devices
connected to AHCI adapters, system resume resets the ATA ports, which
causes connected devices to spin up. In such case, a runtime suspended disk
will incorrectly be seen with a suspended runtime state because the device
is not resumed by sd_resume_system(). The power state seen by the user is
different than the actual device physical power state.

Fix this issue by introducing the struct scsi_device flag
force_runtime_start_on_system_start. When set, this flag causes
sd_resume_system() to request a runtime resume operation for runtime
suspended devices. This results in the user seeing the device runtime_state
as active after a system resume, thus correctly reflecting the device
physical power state.

Fixes: 9131bff6a9f1 ("scsi: core: pm: Only runtime resume if necessary")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231120225631.37938-3-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 87fe8a8..4209fb3 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1055,9 +1055,14 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
                 * Ask the sd driver to issue START STOP UNIT on runtime suspend
                 * and resume and shutdown only. For system level suspend/resume,
                 * devices power state is handled directly by libata EH.
+                * Given that disks are always spun up on system resume, also
+                * make sure that the sd driver forces runtime suspended disks
+                * to be resumed to correctly reflect the power state of the
+                * device.
                 */
                sdev->manage_runtime_start_stop = 1;
                sdev->manage_shutdown = 1;
+               sdev->force_runtime_start_on_system_start = 1;
        }
 
        /*

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 6effa13..e17509f 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3953,8 +3953,15 @@ static int sd_resume(struct device *dev, bool runtime)
 
 static int sd_resume_system(struct device *dev)
 {
-       if (pm_runtime_suspended(dev))
+       if (pm_runtime_suspended(dev)) {
+               struct scsi_disk *sdkp = dev_get_drvdata(dev);
+               struct scsi_device *sdp = sdkp ? sdkp->device : NULL;
+
+               if (sdp && sdp->force_runtime_start_on_system_start)
+                       pm_request_resume(dev);
+
                return 0;
+       }
 
        return sd_resume(dev, false);
 }

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index b919ed2..8fa1153 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -181,6 +181,12 @@ struct scsi_device {
         */
        unsigned manage_shutdown: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.
+        */
+       unsigned force_runtime_start_on_system_start:1;
+
        unsigned removable:1;
        unsigned changed:1;     /* Data invalid due to media change */
        unsigned busy:1;        /* Used to prevent races */