[Letux-kernel] LetuxOS: Kernel: m-stable 5.4.77 successful

[H. Nikolaus Schaller]

> Am 27.11.2020 um 17:31 schrieb Andreas Kemnade <andreas at kemnade.info>:
> 
> On Fri, 27 Nov 2020 16:24:54 +0100
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
> 
>>> Am 27.11.2020 um 14:47 schrieb Andreas Kemnade <andreas at kemnade.info>:
>>>> 
>>> Well,  the symptom was that the code did not compile without alarming
>>> warnings with are treated as errors. Your patch does not fix that. And
>>> while analysing it I found not that the code is broken.  
>> 
>> Ah, now I see. Although there should have been a functional issue by decrementing
>> too much and running tiler_release potentially twice...
>> 
> I have seen several oopses in omap_gem.c which I have not traced down
> all. So some of them might be related.

Yes, I remember some issues especially on poweroff. But I am not aware of them
in newer kernels.

>>> 
>>> My proposal is attached.  
>> 
>> Ok, I think functionally they are the same.
>> 
>> But refcount_dec_and_test() does more tests and enforces a typed argument which
>> ends in your compile error.
>> 
>> So I think we can use your patch equally well. And I will take yours if it avoids
>> redefining the data type of refcount_dec_and_test parameters...
> Well, we would otherwise need to redefine  dma_addr_cnt as it was done
> in 
> 
> commit cec4fa7511ef7a73eb635834e9d85b25a5b47a98
> Author: Jean-Jacques Hiblot <jjhiblot at ti.com>
> Date:   Thu Oct 10 13:59:53 2019 +0200
> 
>    drm/omap: use refcount API to track the number of users of dma_addr
> 
> And then the tiler patch was applied on top of that and cherry-picked
> and that produced the mess.

Yes that seems to be what went wrong and what we fix now.

BR and thanks,
Nikolaus