Re: [PATCH v2 1/2] drm/i915: Change semantics of context isolation reporting to UM

[Petr Vorel <pvorel@suse.cz>]

Hi all,

> From: Adrian Larumbe <adrian.larumbe@collabora.com>

> I915_PARAM_HAS_CONTEXT_ISOLATION was already being used as a boolean by
> both Iris and Vulkan, and stood for the guarantee that, when creating a
> new context, it would not contain register state from preexisting ones.

> However, the actual param ioctl was returning a bitmask for the
> engines in which isolation is supported, and IGT gem_ctx_isolation was
> exploiting this wrong semantics when making decisions about which
> engines support it.

> This is a uAPI documentation change that precedes the actual change in
> the getparam ioctl.

> Signed-off-by: Adrian Larumbe <adrian.larumbe@collabora.com>
> Signed-off-by: Krzysztof Niemiec <krzysztof.niemiec@intel.com>
> ---
>  include/uapi/drm/i915_drm.h | 4 ----
>  1 file changed, 4 deletions(-)

> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 535cb68fdb5c..5aff550034fc 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -724,10 +724,6 @@ typedef struct drm_i915_irq_wait {
>   * supports) that all state set by this context will not leak to any other
>   * context.
>   *
nit: could you please remove also this trailing line above which contains only
'*'?

Kind regards,
Petr

> - * As not every engine across every gen support contexts, the returned
> - * value reports the support of context isolation for individual engines by
> - * returning a bitmask of each engine class set to true if that class supports
> - * isolation.
>   */
>  #define I915_PARAM_HAS_CONTEXT_ISOLATION 50