[PATCH v3 RESEND 21/24] drm/exynos/decon5433: add local path support

[Marek Szyprowski]

Hi Krzysztof,

On 03.03.2022 17:03, Krzysztof Kozlowski wrote:
> On 02/03/2022 02:00, Inki Dae wrote:
>> 22. 2. 7. 01:51에 Krzysztof Kozlowski 이(가) 쓴 글:
>>> On 25/03/2019 08:13, Andrzej Hajda wrote:
>>>> GSCALERs in Exynos5433 have local path to DECON and DECON_TV.
>>>> They can be used as extra planes with support for non-RGB formats and scaling.
>>>> To enable it on DECON update_plane and disable_plane callback should
>>>> be modified. Moreover DSD mux should be set accordingly, and finally
>>>> atomic_check callback should be used to limit the number of active planes.
>>>>
>>>> Signed-off-by: Andrzej Hajda <a.hajda at samsung.com>
>>>> ---
>>>>   drivers/gpu/drm/exynos/exynos5433_drm_decon.c | 80 +++++++++++++++----
>>>>   drivers/gpu/drm/exynos/regs-decon5433.h       |  6 ++
>>>>   2 files changed, 72 insertions(+), 14 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/ex
>>> Hi guys!
>>>
>>> I am working on DRM bindings conversion to DT schema format and I found
>>> this set only partially applied. I merged the DTS patches ("dsd" clock),
>>> but I think the driver and bindings were not picked up.
>>>
>>> Nevertheless I am going to include the "dsd" clock in the new bindings,
>>> so the DTS passes DT schema checks. Let me know if other approach
>>> (revert of DTS change) should be taken.
>>>
>> Sorry for late response.
>>
>> As of now, "dsd" is a dead property not used anywhere.
>> This patch series makes real user not to work correctly due to ABI change.
>> How about reverting it until this patch series is merged after fixing the real user problem?
> The Exynos5433 DECON bindings were already merged by Rob, so someone
> would need to send a revert. However this does not answer the actual
> question - whether the "dsd" clock is necessary, whether it is there
> (routed to DECON). If it is, it should stay in the bindings.

It is routed to DECON hardware and enabling it is needed to make the so 
called 'local path' (when DECON takes image data directly from the 
GSCALER hardware block instead of the memory buffer) working.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland