[U-Boot] UBI: regression since "mtd: ubi: Fix worker handling"

[Richard Weinberger <richard@nod.at>]

Am Dienstag, 22. Mai 2018, 08:30:45 CEST schrieb Heiko Schocher:
> Hello Richard,
> 
> Am 21.05.2018 um 21:31 schrieb Richard Weinberger:
> > Patrice,
> > 
> > Am Montag, 21. Mai 2018, 16:07:41 CEST schrieb Richard Weinberger:
> >>>    		e->pnum = aeb->pnum;
> >>>    		e->ec = aeb->ec;
> >>>    		ubi->lookuptbl[e->pnum] = e;
> >>> +		ubi->thread_enabled = 1;
> >>
> >> This is not correct. At this point the UBI thread is not ready.
> >> I know, I know, U-Boot has no threads but some data structures might
> >> not be ready.
> >>
> >> Let me think how to work around this properly.
> > 
> > The root cause seems to be that U-Boot misses this fix from Linux:
> > 
> > commit 1cb8f9776c7dcadc57885c6653943511d282633b
> > Author: Richard Weinberger <richard@nod.at>
> > Date:   Tue Aug 11 23:27:44 2015 +0200
> > 
> >      ubi: fastmap: Implement produce_free_peb()
> >      
> >      If fastmap requests a free PEB for a pool and UBI is busy
> >      with erasing PEBs we need to offer a function to wait for one.
> >      We can reuse produce_free_peb() from the non-fastmap WL code
> >      but with different locking semantics.
> >      
> >      Cc: stable at vger.kernel.org # 4.1.x-
> >      Reported-and-tested-by: Jörg Krause <joerg.krause@embedded.rocks>
> >      Signed-off-by: Richard Weinberger <richard@nod.at
> > 
> > Heiko, I'm currently working on Fastmap in Linux[0].
> > I suggest to re-syncing with Linux if my changes go upstream, I can ping you them. :-)
> > Fastmap gained many improvements since the last sync.
> 
> Yes, but I am currently under load, and doing a rebase is a bigger
> task I fear (I speculate currently to automate this task with tbot,
> let me think a little bit about this, if this would work, U-Boot UBI
> would autaomtically follow linux tree, and I immediately would see
> merge errors ...)

Ok. :-)

> Also before a rebase can go mainline, we need deep testing. So no
> fast chance here for me ... sorry. If we can find commits, which
> fix this regression, it may makes sense to apply them before such a
> rebase ... ?

As I said, commit 1cb8f9776c7dcadc57885c6653943511d282633b should do the trick.
Patrice, can you please give it a try?

Thanks,
//richard