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

[Patrice CHOTARD]

Hi Richard, Heiko

On 05/22/2018 08:51 AM, Patrice CHOTARD wrote:
> 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?

I confirm this patch fixes the issue.

Thanks for your reactivity ;-)

Patrice

> 
> Yes sure,
> 
> Thanks
> 
> Patrice
> 
>>
>> Thanks,
>> //richard
>>