[Mesa-stable] [Mesa-dev] [PATCH] nouveau: take extra push space into account for pushbuf_space calls

[Emil Velikov]

On 11 January 2017 at 03:10, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> Ever since a long time ago when I messed around with fences, I ensure
> that after a PUSH_SPACE call there is enough space to write a fence out
> into the pushbuf.
>
> However the PUSH_SPACE macro is not all-knowing, and so sometimes we
> have to invoke nouveau_pushbuf_space manually with the relocs/pushes
> args set. If we don't take the extra allocation from PUSH_SPACE into
> account, then we will end up accidentally flushing when the code was not
> expecting a flush. This can lead to various runtime and rendering
> failures.
>
The previous calculations were ~ok to figure out, while these are less so.
For posterity, please add a comment/note somewhere how these are
derived. Pretty much anything will do.

Thanks
Emil