Re: [PATCH RFC v1 1/1] scsi: pm: Leave runtime resume along if block layer PM is enabled

[Bart Van Assche <bvanassche@acm.org>]

On 11/15/20 5:42 PM, Can Guo wrote:
> Actually, I am thinking about removing all the pm_runtime_set_active()
> codes in both scsi_bus_resume_common() and scsi_dev_type_resume() - we
> don't need to forcibly set the runtime PM status to RPM_ACTIVE for either
> SCSI host/target or SCSI devices.
> 
> Whenever we access one SCSI device, either block layer or somewhere in
> the path (e.g. throgh sg IOCTL, sg_open() calls scsi_autopm_get_device())
> should runtime resume the device first, and the runtime PM framework makes
> sure device's parent (and its parent's parent and so on)gets resumed as
> well.
> Thus, the pm_runtime_set_active() seems redundant. What do you think?

Hi Can,

It is not clear to me why the pm_runtime_set_active() calls occur in the
scsi_pm.c source file since the block layer automatically activates
block devices if necessary. Maybe these calls are a leftover from a time
when runtime suspended devices were not resumed automatically by the
block layer? Anyway, I'm fine with removing these calls.

Thanks,

Bart.