On 26/01/17 06:47 AM, Michael wrote:
> Hello,
>
> On Wed, 18 Jan 2017 11:24:03 +0900
> Michel Dänzer <mic...@daenzer.net> wrote:
>
>>>>> The Creator is weirder - it's got what Sun calls '3dRAM' - little ALUs
>>>>> built into the memory chips which can do things like ROPs and alpha
>>>>> blending. So basically you can set up a few registers, then write a
>>>>> texture into memory and have it PictOpOver-ed at more or less the speed
>>>>> you can get it through the UPA bus. The 'blitter' has no copy
>>>>> operation, and it can't handle A8 textures, so storing textures in video
>>>>> RAM is useless. Also, its organization is weird and, for off-screen
>>>>> areas, undocumented.
>>>>> What would be a sane way to make EXA deal with these?
>>>>
>>>> The driver's CheckComposite hook could inspect the destination picture,
>>>> and only return true if its drawable points into VRAM.
>>>
>>> That's what I tried first - EXA won't even get to PrepareComposite()
>>> unless all involved pictures are in VRAM.
>>
>> Sounds like the "classic" EXA mode, where the core EXA code is in full
>> control of managing "offscreen" (i.e. GPU accessible) memory. There are
>> "mixed" and "driver" modes, providing increasing levels of control over
>> this to the driver. See exa/{exa_driver,exa_migration_mixed,exa_mixed}.c .
>
> Thanks for the hint - I'm playing with this right now.
> So if I'm not completely mistaken, this way I can just pretend that all
> pixmaps are usable by the accelerator in general, weed out the
> impossible cases in Prepare*() and avoid any and all unnecessary
> migration?
Yeah, that's basically it.
--
Earthling Michel Dänzer | http://www.amd.com
Libre software enthusiast | Mesa and X developer
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