[Intel-gfx] [PATCH] drm/i915/selftests: add test to verify get/put fw domains

[Daniele Ceraolo Spurio]

<snip>

> +
> +	for_each_engine(engine, i915, id) {
> +		i915_reg_t offset = RING_START(engine->mmio_base);

I had a failure on the BCS on gen8 with this register in my trybot run. 
Maybe we can use RING_MI_MODE instead? if we wait for idle at the 
beginning of the test we should always have the IDLE bit set, so we're 
guaranteed a non-zero value with FW.

Daniele