[Nouveau] [PATCH 4/5] gr/gf100: wait on bottom half of FE's pipeline

[Alexandre Courbot]

On Mon, Jun 8, 2015 at 10:43 PM, Alexandre Courbot <gnurou at gmail.com> wrote:
> On Mon, Jun 8, 2015 at 8:04 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> A naive question from someone who knows nothing of icmd or bundles... Would
>> it be better to wait for both bits to become 0 (I.e. 0x6)?
>
> My understanding is that a method reaching the bottom half implies it
> has passed to upper half (whatever these halfs are, I need to dig into
> the doc to completely figure it out), and thus that while waiting for
> both bits would do no harm, it would not do any good either.
>
> Waiting on the bottom half is what downstream does, so I think this
> behavior is safe to apply to Nouveau.

After checking, this seems to be correct. Upper half of the front-end
method pipeline corresponds to the decode stage, bottom half to
validate and emit. So we need to wait on the bottom half to be sure
methods are emitted.