[Intel-gfx] [PATCH] drm/i915: Apply context workarounds directly

[Joonas Lahtinen]

Quoting Chris Wilson (2018-06-15 19:37:33)
> From: Oscar Mateo <oscar.mateo at intel.com>
> 
> Once upon a time, we tried to apply workarounds for registers that lived
> inside the context image for every new context. That meant emitting LRI
> commands soon after each context was created.
> 
> Nowadays, we have a single golden context that gets used as a master
> template for future contexts. That golden context will acquire initial
> values for its image from the existing values in HW (thanks to inhibit
> restore bit). If all WAs are applied normally (i.e. using MMIO writes)
> before that happens, they will get soaked up by the golden context and
> transmitted correctly to new contexts.
> 
> All of this means we don't have to distinguish between context and
> non-context WAs anymore, because both can be applied in the same way
> (we still want to distinguish them though, because we would like to
> check their validity using i-g-t, and that means making sure we have
> a context loaded for ctx-residing WAs).
> 
> Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas