On 9/12/19 7:35 AM, Stanley Chu wrote:
> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index 64c96c7828ee..461aafadd208 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -1300,7 +1300,8 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
> device_enable_async_suspend(&sdev->sdev_gendev);
> scsi_autopm_get_target(starget);
> pm_runtime_set_active(&sdev->sdev_gendev);
> - pm_runtime_forbid(&sdev->sdev_gendev);
> + if (sdev->rpm_autosuspend_delay < 0)
> + pm_runtime_forbid(&sdev->sdev_gendev);
> pm_runtime_enable(&sdev->sdev_gendev);
> scsi_autopm_put_target(starget);
So we have a single new struct member, rpm_autosuspend_delay, that
controls two different behaviors: (a) whether or not runtime suspend is
enabled at device creation time and (b) the power management autosuspend
delay. I don't like this. Should two separate variables be introduced
instead of using a single variable to control both behaviors?
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 202f4d6a4342..133b282fae5a 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -199,7 +199,7 @@ struct scsi_device {
> unsigned broken_fua:1; /* Don't set FUA bit */
> unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */
> unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */
> -
> + int rpm_autosuspend_delay;
> atomic_t disk_events_disable_depth; /* disable depth for disk events */
>
> DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
>
Since the default value for the autosuspend delay is the same for all
SCSI devices attached to a SCSI host is the same, please add a variable
with the same name in the SCSI host template and use that value as the
default value for SCSI devices. If the rpm_autosuspend_delay variable
only occurs in struct scsi_device then LLD authors are forced to
introduce a slave_configure function. Introducing such a function can be
avoided if the default autosuspend delay can be specified in the host
template.
Bart.
