Dne sreda, 27. junij 2018 ob 22:58:28 CEST je Jernej Škrabec napisal(a):
Dne sreda, 27. junij 2018 ob 20:25:00 CEST je Maxime Ripard napisal(a):
Hi!
On Wed, Jun 27, 2018 at 06:45:14PM +0200, Jernej Skrabec wrote:
Initial implementation of DE2 planes only supported fixed zpos.
Expand implementation with configurable zpos property.
Signed-off-by: Jernej Skrabec jernej.skrabec@siol.net
Thanks for that work. I guess you should expand a bit on the exact setup you're doing here.
OK.
Are the pipes working the same way on the DE2 than on DE1, ie does the pipe blending applies before the alpha blending, and therefore you need to make sure that there's not two planes with alpha going to the same pipe?
I'm not familiar with DE1 and I'm not sure what the problem is.
However, there is an issue in DE2 when alpha blending multiple planes if bottom-most plane doesn't cover all screen. In this case alpha blending produce weird result on screen. Fortunately, there is elegant solution. Black opaque fill color is enabled for pipe 0 (always at the bottom), which covers any "undefined region" and that makes alpha blending happy again.
Alternatively, blending modes between planes could be tweaked or disabled, but I found aforementioned solution is much simpler and you set it only once.
I forgot to test one corner case - what happens if pipe 0 has alpha channel enabled. I think it still has to work, since there is background color which IMO is meant for such cases.
Also, you seem to use the pipe and channels indifferently now, why is that?
Why do you think so?
Channel always represents HW unit, for example, on H3, mixer0, channel 0 always represents VI plane, channel 1, represents first UI, plane, channel 2, second UI plane, etc.
Pipe 0 always represent channel at the bottom, pipe 1 channel on top pipe 0, etc. Initial, fixed zpos implementation really had 1:1 mapping, but now it can be different.
Register SUN8I_MIXER_BLEND_ROUTE holds pipe <-> channel mappings. Bits 3:0 represents pipe 0 and holds channel number. Bits 7:4 represents pipe 1, etc.
Additionaly, there can be holes, for example, pipe 3 and pipe 0 are enabled and pipe 1 and 2 are disabled.
I hope I answered your questions.
Looking at DE2.0 documentation, chapter 5.10.2 (pp. 87) might give you some answers. Block diagram seems much simpler than that of DE1.
Best regards, Jernej