[Intel-gfx] [PATCH 21/39] drm/i915/guc: Disable global reset

[Daniele Ceraolo Spurio]

On 01/02/2019 01:41 AM, Chris Wilson wrote:
> The guc (and huc) currently inexcruitably depend on struct_mutex for
> device reinitialisation from inside the reset, and indeed taking any
> mutex here is verboten (as we must be able to reset from underneath any
> of our mutexes). That makes recovering the guc unviable without, for
> example, reserving contiguous vma space and pages for it to use.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_reset.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
> index f5da67f1bc04..77fc2f74e427 100644
> --- a/drivers/gpu/drm/i915/i915_reset.c
> +++ b/drivers/gpu/drm/i915/i915_reset.c
> @@ -590,6 +590,9 @@ int intel_gpu_reset(struct drm_i915_private *i915, unsigned int engine_mask)
>   
>   bool intel_has_gpu_reset(struct drm_i915_private *i915)
>   {
> +	if (USES_GUC(i915))
> +		return false;
> +

Do we need to tweak the getparam so we can report that we have engine 
reset but not full reset?

Also, this is a regression of capabilities when GuC is enabled, so we 
need to make lockless reset work with GuC soon. Were you already 
planning/working on something along the lines of the possible solution 
mentioned in the commit message? Just trying to understand what the 
status is before jumping in to avoid duplication of work ;)

Thanks,
Daniele

>   	return intel_get_gpu_reset(i915);
>   }
>   
>