Re: [PATCH] drm/exynos: remove hardware overlays disable from fimd probe

[Andrzej Hajda <a.hajda@samsung.com>]

On 06/02/2014 12:11 PM, Tomasz Figa wrote:
> Hi Rahul, Andrzej,
> 
> On 02.06.2014 11:42, Rahul Sharma wrote:
>> On 2 June 2014 14:41, Andrzej Hajda <a.hajda@samsung.com> wrote:
>>> Hi Rahul,
>>>
>>> On 05/28/2014 08:11 AM, Rahul Sharma wrote:
>>>> System hangs when FIMD registers are accessed to disable
>>>> hardware overlays. This is because of the clocks which are
>>>> not enabled before register access.
>>>>
>>>> 'Hardware overlay disable' is cleaned from the FIMD probe.
>>>>
>>>> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
>>>
>>> This patch causes regression on some exynos4210-universal_c210 devices,
>>> everything works expect colors are incorrect - it seems blue component
>>> is very dark, almost black.
>>>
>>
>> Oh.... Sorry for that. I did not see any problem on 5250/5420/5800. I do not
>> have setup for 4210. Better we should revert this patch.
>>
>> Would you please help me by verifying the following patch on 4210? This
>> is an alternate solution to the same problem.
>>
>> http://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg31426.html
>>
>> Thanks Andrej, for bringing it to notice.
> 
> I don't see how this patch could introduce such regression, as all the
> affected registers seem to be properly reconfigured in fimd_win_commit()
> anyway.
> 
> IMHO instead of reverting the patch, this issue should be investigated
> and fixed properly.
> 
> Best regards,
> Tomasz
> 

I am looking at the problem, it is quite strange as it happens only on
one of two targets I have access to. Anyway it seems that something
should be added to fimd initialization sequence if we want to remove hw
accessing code from probe.

Regards
Andrzej