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

Message ID 20220406094654.29722-2-rex-bc.chen@mediatek.com
State Changes Requested, archived
Headers show
Series Correct disp_aal dt-binding | expand

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Commit Message

Rex-BC Chen (陳柏辰) April 6, 2022, 9:46 a.m. UTC
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(-)

Comments

Krzysztof Kozlowski April 6, 2022, 2:44 p.m. UTC | #1
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
Rex-BC Chen (陳柏辰) April 7, 2022, 6:22 a.m. UTC | #2
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
Krzysztof Kozlowski April 7, 2022, 6:49 a.m. UTC | #3
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
Rex-BC Chen (陳柏辰) April 7, 2022, 8:38 a.m. UTC | #4
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
diff mbox series

Patch

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