[Mesa-dev] [PATCH 1/2] i965: add missing rollback of URB requirements

[Chris Wilson]

Quoting Lionel Landwerlin (2019-01-08 11:03:26)
> Hi Andrii,
> 
> Although I think what these patches do makes sense, I think it's missing 
> the bigger picture.
> There is a lot more state that gets lost if we have to revert all of the 
> emitted commands.
> A quick look at brw_upload_pipeline_state() shows all of the programs 
> could be invalid as well, or the number of samples, etc...
> 
> To me it seems like we need a much larger state save/restore.
> 
> Ken: what do you think?

How about not rolling back? If we accept it as currently broken, and just
demand the kernel provide logical contexts for all i965 devices (just ack
some patches!), and then just flush the batch (possibly with a dummy 3D
prim if you want to be sure the 3D state is loaded) and rely on the
context preserving state across batches.
-Chris