[Intel-gfx] [PATCH 09/34] drm/i915/guc: Disable global reset

[John Harrison]

On 1/21/2019 14:20, 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.
>
> The plan to re-enable global reset for the GuC centres around reusing the
> WOPM reserved space at the top of the aperture (that we know we can
> populate a contiguous range large enough to dma xfer the fw image).
>
> In the meantime, hopefully no one even notices as the device-reset is
> only used as a backup to the per-engine resets for handling GPU hangs.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Acked-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Acked-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> ---
>   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 b9d0ea70361c..2961c21d9420 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;
> +
>   	return intel_get_gpu_reset(i915);
>   }
>   

Reviewed-by: John Harrison <John.C.Harrison at Intel.com>