[PATCH v4 01/11] mtd: core: always create master device

[Usyskin, Alexander]

> >> > This streamlines device tree and allows to anchor
> >> > runtime power management on master device in all cases.
> >>
> >> Please explain in more detail why this is needed.
> >> If this change makes the overall situation better and breaks
> >> no userspace, I'm happy. :-)
> >>
> >
> > The rest of the series is a driver that need runtime power management.
> > Absence of the master device breaks power management logic,
> > as kernel automatically propagates state from children to parent.
> > I initially hooked runtime_pm on chip auxiliary device, but this is a hack,
> > not a solution.
> 
> So, the problem is that mtd partitions don't have a common parent/master
> like
> we have for generic disks?
> Please give more details.
> We have already a non-optimal situation in mtd and I want to fully understand
> the requirements to get it this time right.
> 

Yes, the mtd may have master, if CONFIG_MTD_PARTITIONED_MASTER is set,
but it came with forced partition and usually unset in generic distributions.
If CONFIG_MTD_PARTITIONED_MASTER is unset the dev structure 
is not initialized in full.
I've tried to preserve status-quo when CONFIG_MTD_PARTITIONED_MASTER is set
and introduce initialized master device structure otherwise.

> Thanks,
> //Richard


- - 
Thanks,
Sasha