This is a note to let you know that I've just added the patch titled
scsi: sd: Fix system start for ATA devices
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-sd-fix-system-start-for-ata-devices.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b09d7f8fd50f6e93cbadd8d27fde178f745b42a1 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
Date: Tue, 21 Nov 2023 07:56:31 +0900
Subject: scsi: sd: Fix system start for ATA devices
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231120225631.37938-3-dlemoal@xxxxxxxxxx
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ata/libata-scsi.c | 5 +++++
drivers/scsi/sd.c | 9 ++++++++-
include/scsi/scsi_device.h | 6 ++++++
3 files changed, 19 insertions(+), 1 deletion(-)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1055,9 +1055,14 @@ int ata_scsi_dev_config(struct scsi_devi
* 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;
}
/*
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3953,8 +3953,15 @@ static int sd_resume(struct device *dev,
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);
}
--- 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 */
Patches currently in stable-queue which might be from dlemoal@xxxxxxxxxx are
queue-6.6/scsi-sd-fix-system-start-for-ata-devices.patch
queue-6.6/scsi-change-scsi-device-boolean-fields-to-single-bit-flags.patch
