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

[Patrice CHOTARD]

Hi

On 05/22/2018 08:37 AM, Richard Weinberger wrote:
> 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 at 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 at embedded.rocks>
>>>       Signed-off-by: Richard Weinberger <richard at 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?

Yes sure,

Thanks

Patrice

> 
> Thanks,
> //richard
>