Texture alignment and layout problem

[yuq]

Dump the mali 260x260 FBO draw with:
https://github.com/yuq/gfx/tree/master/x11/fbo

Output:
https://gist.github.com/yuq/a17350bd5bf91dbeba24e9deeda9a829
https://gist.github.com/yuq/a32a5ed635bfffe27c49b936a06c4887

Seems the texture memory will be reused and no copy:

1. frame 0 output to 0x10100000
2. frame 1 get texture from 0x10100000
3. 0x10100000 memory not changed from the end of frame 0 to beginning of frame 1

The memory content at 0x10100000 is not linear and the layout field in pp frame wb0 and texture desc are set. Maybe some tiled format or mipmap?

Need more investigation.

[anarsoul]

Looks like a tiled format.

[yuq]

Help from Alyssa:
"
Utgard and Midgard have identical formats for tiled textures. So, I
modified the limare code for texture tiling to improve the flexibility
and maybe performance. It might be useful for lima.
https://gitlab.freedesktop.org/panfrost/panloader/blob/develop/trans/limare-swizzle.c
"

[anarsoul]

We also need untiling routine. Basically we need to plug tiling/untiling routines into lima_transfer_map() and lima_transfer_unmap(). Scanout buffer should be kept untiled, but it cannot be used as texture later (at least not without a copy).

[yuq]

Yes, we need it anyway. If mali GPU has a format converter DMA, we can use it too. I see in mali kernel driver there's DMA IOREG but never used.

I still doubt that mali doesn't support aligned linear texture. Maybe only because we haven't found where's the setting. I'm thinking if there's a case that mali binary driver has to use an aligned linear texture so that we can write a test for dump.

[anarsoul]

Tiled textures should be faster, so we'll have to support them anyway. As for aligned linear textures - limare comment says that proprietary driver uses linear format for large textures. So could you try running your demo with 1300x1300 texture?

[yuq]

Tried 1300x1300, same tiled texture. I think I have to setup a mali driver supporting gbm interfaces for this.

[anarsoul]

@yuq could you try setting layout to 1 or 2 in lima_update_tex_desc() in lima? I don't have access to my setup atm to test.

[yuq]

What's the purpose of this? I'm investigating the aligned linear texture desc setup, not the tiled texture desc setup.

[anarsoul]

@yuq layout = 3 enables tiling, and looks like pitch is aligned to 16 in this case. layout = 0 is linear, and pitch equals width. I wonder if layout = 1 or layout = 2 is linear texture with aligned pitch.

[shadeslayer]

I tried running weston and Plasma with layout = 1 and 2 ( as well as setting flag0 to both 0 or 1 ).

With Weston, on all 4 configurations, I got nothing on the screen.
With Plasma, on all 4 configurations, I got a garbled cursor on the screen.

So perhaps linear textures don't work?