[PATCH v3 13/14] drm/mediatek: Support DRM plane alpha in OVL

[Jason-JH Lin (林睿祥)]

> Jason:
> That is a lot of information, and quite above my head! Thank you
> though.
> 
> I should note that the log items I sent you are from the "good"
> kernel - 
> 6.11 with the commit reverted. Here is a much longer set of logs: 
> https://termbin.com/co6v
> 
> I've rebuild 6.11 with the log statement enabled and the "bad"
> behavior.
> Here is a dmesg from that: https://termbin.com/xiev
> 
Hi Adam,

I think something wrong with your dmesg links, both logs look the same.
We should see this log in the "bad" one:
fmt:0x34325258, has_alpha:0x0, alpha:0xffff, con:0x2000

But anyway, I think the reason for the downgrade is clear enough to me.
So let's try to figure out the solution.

> These logs are both from `dmesg`.
> 
> I'm fairly certain I've built with the patch you referenced enabled.
> The 
> kernels I run are just release kernels, not RCs or git branches or 
> anything. The mainline v6.11 kernel is the one that has this problem.
> If 
> that patch has been merged into 6.11 (which, looks like it has) then 
> it's in the kernel I'm building.

Got it.
Then OVL_CONST_BLEND might be the unsupported configuration in MT8173,
I think we should remove the XRGB8888 format for MT8173.

Could you please try this modification and see if it'll change to use
others supported format to show the text?

--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -102,12 +102,9 @@ static inline bool is_10bit_rgb(u32 fmt)
 }

 static const u32 mt8173_formats[] = {
-       DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
-       DRM_FORMAT_BGRX8888,
        DRM_FORMAT_BGRA8888,
        DRM_FORMAT_ABGR8888,
-       DRM_FORMAT_XBGR8888,
        DRM_FORMAT_RGB888,
        DRM_FORMAT_BGR888,
        DRM_FORMAT_RGB565,


Regards,
Jason-JH.Lin

> 
> - Adam Thiede