[PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183

Rex-BC Chen posted 3 patches 2 years, 5 months ago
[PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Rex-BC Chen 2 years, 5 months ago
The driver data of MT8183 and MT8173 are different.
The value of has_gamma for MT8173 is true while the value of MT8183 is
false. Therefore, the compatible of disp_aal for MT8183 is not suitable
for the compatible for MT8173.

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 .../devicetree/bindings/display/mediatek/mediatek,aal.yaml  | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
index cb4a2f39ff88..f118075e4a89 100644
--- a/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
+++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
@@ -21,12 +21,12 @@ description: |
 properties:
   compatible:
     oneOf:
-      - items:
-          - const: mediatek,mt8173-disp-aal
+      - enum:
+          - mediatek,mt8173-disp-aal
+          - mediatek,mt8183-disp-aal
       - items:
           - enum:
               - mediatek,mt2712-disp-aal
-              - mediatek,mt8183-disp-aal
               - mediatek,mt8192-disp-aal
               - mediatek,mt8195-disp-aal
           - const: mediatek,mt8173-disp-aal
-- 
2.18.0
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by AngeloGioacchino Del Regno 2 years, 5 months ago
Il 06/04/22 11:46, Rex-BC Chen ha scritto:
> The driver data of MT8183 and MT8173 are different.
> The value of has_gamma for MT8173 is true while the value of MT8183 is
> false. Therefore, the compatible of disp_aal for MT8183 is not suitable
> for the compatible for MT8173.
> 
> Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>

Hello!
Yes, I definitely agree with this change, it makes no sense to have both
8173 and 8183 compatibles for 8183 (and similar).

Though, please, add a note in this commit message advertising that the
mistake was only in the yaml binding, as the driver doesn't require any
functional changes, so that things are clear for people with less expertise
on MediaTek platforms.

After that:
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Rex-BC Chen 2 years, 5 months ago
On Wed, 2022-04-06 at 12:38 +0200, AngeloGioacchino Del Regno wrote:
> Il 06/04/22 11:46, Rex-BC Chen ha scritto:
> > The driver data of MT8183 and MT8173 are different.
> > The value of has_gamma for MT8173 is true while the value of MT8183
> > is
> > false. Therefore, the compatible of disp_aal for MT8183 is not
> > suitable
> > for the compatible for MT8173.
> > 
> > Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> 
> Hello!
> Yes, I definitely agree with this change, it makes no sense to have
> both
> 8173 and 8183 compatibles for 8183 (and similar).
> 
> Though, please, add a note in this commit message advertising that
> the
> mistake was only in the yaml binding, as the driver doesn't require
> any
> functional changes, so that things are clear for people with less
> expertise
> on MediaTek platforms.
> 
> After that:
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>

Hello Angelo,

Thanks for your review.
I will add them to the commit message in next version.

BRs,
Rex
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Krzysztof Kozlowski 2 years, 5 months ago
On 06/04/2022 11:46, Rex-BC Chen wrote:
> The driver data of MT8183 and MT8173 are different.
> The value of has_gamma for MT8173 is true while the value of MT8183 is
> false. Therefore, the compatible of disp_aal for MT8183 is not suitable
> for the compatible for MT8173.

Just because one feature is not supported, it does not mean they are
incompatible, which you claim in the patch below. Are you sure they are
really incompatible and MT8173 fallback cannot be used?


Best regards,
Krzysztof
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Rex-BC Chen 2 years, 5 months ago
On Wed, 2022-04-06 at 16:44 +0200, Krzysztof Kozlowski wrote:
> On 06/04/2022 11:46, Rex-BC Chen wrote:
> > The driver data of MT8183 and MT8173 are different.
> > The value of has_gamma for MT8173 is true while the value of MT8183
> > is
> > false. Therefore, the compatible of disp_aal for MT8183 is not
> > suitable
> > for the compatible for MT8173.
> 
> Just because one feature is not supported, it does not mean they are
> incompatible, which you claim in the patch below. Are you sure they
> are
> really incompatible and MT8173 fallback cannot be used?
> 
> 
> Best regards,
> Krzysztof

Hello Krzysztof,

Thanks for your review.

The difference of disp_aal for each MediaTek SoCs is "has_gamma".
And we only control this variable for different MediaTek SoCs.

The value of has_gamma for MT8173 is true.
The value of has_gamma for MT8183 is false. (Moreover, the driver data
is null for MT8183)

From this situation, I think it's not compatible between MT8173 and
MT8183.

reference: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/mediatek/mtk_disp_aal.c?h=v5.18-rc1#n153

BRs,
Rex
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Krzysztof Kozlowski 2 years, 5 months ago
On 07/04/2022 08:22, Rex-BC Chen wrote:
> On Wed, 2022-04-06 at 16:44 +0200, Krzysztof Kozlowski wrote:
>> On 06/04/2022 11:46, Rex-BC Chen wrote:
>>> The driver data of MT8183 and MT8173 are different.
>>> The value of has_gamma for MT8173 is true while the value of MT8183
>>> is
>>> false. Therefore, the compatible of disp_aal for MT8183 is not
>>> suitable
>>> for the compatible for MT8173.
>>
>> Just because one feature is not supported, it does not mean they are
>> incompatible, which you claim in the patch below. Are you sure they
>> are
>> really incompatible and MT8173 fallback cannot be used?
>>
>>
>> Best regards,
>> Krzysztof
> 
> Hello Krzysztof,
> 
> Thanks for your review.
> 
> The difference of disp_aal for each MediaTek SoCs is "has_gamma".
> And we only control this variable for different MediaTek SoCs.
> 
> The value of has_gamma for MT8173 is true.
> The value of has_gamma for MT8183 is false. (Moreover, the driver data
> is null for MT8183)
> 
> From this situation, I think it's not compatible between MT8173 and
> MT8183.

You repeated the commit msg without bringing any new information... but
let it be, I assume setting gamma on MTT8183 is incorrect or produces
wrong results.


Best regards,
Krzysztof
Re: [PATCH 1/3] dt-bindings: display: mediatek: Correct disp_aal binding for MT8183
Posted by Rex-BC Chen 2 years, 5 months ago
On Thu, 2022-04-07 at 08:49 +0200, Krzysztof Kozlowski wrote:
> On 07/04/2022 08:22, Rex-BC Chen wrote:
> > On Wed, 2022-04-06 at 16:44 +0200, Krzysztof Kozlowski wrote:
> > > On 06/04/2022 11:46, Rex-BC Chen wrote:
> > > > The driver data of MT8183 and MT8173 are different.
> > > > The value of has_gamma for MT8173 is true while the value of
> > > > MT8183
> > > > is
> > > > false. Therefore, the compatible of disp_aal for MT8183 is not
> > > > suitable
> > > > for the compatible for MT8173.
> > > 
> > > Just because one feature is not supported, it does not mean they
> > > are
> > > incompatible, which you claim in the patch below. Are you sure
> > > they
> > > are
> > > really incompatible and MT8173 fallback cannot be used?
> > > 
> > > 
> > > Best regards,
> > > Krzysztof
> > 
> > Hello Krzysztof,
> > 
> > Thanks for your review.
> > 
> > The difference of disp_aal for each MediaTek SoCs is "has_gamma".
> > And we only control this variable for different MediaTek SoCs.
> > 
> > The value of has_gamma for MT8173 is true.
> > The value of has_gamma for MT8183 is false. (Moreover, the driver
> > data
> > is null for MT8183)
> > 
> > From this situation, I think it's not compatible between MT8173 and
> > MT8183.
> 
> You repeated the commit msg without bringing any new information...
> but
> let it be, I assume setting gamma on MTT8183 is incorrect or produces
> wrong results.
> 
> 
> Best regards,
> Krzysztof

Hello Krzysztof,

Sorry for this.
I can explain more detailed.

For MT8173, the gamma module is inside disp_aal. When we need to adjust
gamma value, we need to use "has_gamma" to control gamma function
inside disp_aal to adjust gamma value.

Since MT8183 (MT8192/MT8195/MT8186), display gamma is seperated from
disp_aal. We just need to control disp_gamma directly and we don't need
to control gamma function inside disp_aal.

I will add these comments to commit message in next version to explain
it.

BRs,
Rex