[Mesa-dev] [RFC v3 13/23] vulkan/wsi: Move linear alloc into radv

[Daniel Stone]

Hi,

On 28 September 2017 at 09:10, Dave Airlie <airlied at gmail.com> wrote:
> If we get a nouveauv ever we would have to have this, so not really wanting
> this.

Thanks for taking a look. The reason I did this wasn't just to get it
out of the WSI, but because we need it in the driver anyway.

Without modifiers, it's easy: we need a linear copy when we have a
'different' GPU as a consumer, and not otherwise.

With modifiers, that becomes harder. Intel and AMD _do_ support common
tiling formats (the DX-mandated ones: Intel calls the family Yf), so
whenever AMD gets modifier support, you could skip the blit-to-linear
in that case. But the reverse holds true as well: the WSI can
advertise a set of modifiers the driver can't / doesn't want to render
directly to, where a blit would be needed. The WSI can't actually know
that, only the driver.

I can imagine something like an out param for the driver's alloc
callback telling WSI that it needs a linear surface allocated to blit
to as well, but it didn't seem like that was actually saving any code.
Any ideas?

Cheers,
Daniel