[Intel-gfx] [PATCH] drm/i915: Extend reset modparam to domain resets

[Chris Wilson]

Quoting Stuart Summers (2019-11-20 17:36:42)
> In the event a platform does not properly implement reset,
> do not go through reset flows for engine domains to avoid
> an unlikely situation where writes are accepted but register
> values are never cleared, as this can result in GPU wedges
> in these cases.
> 
> Signed-off-by: Stuart Summers <stuart.summers at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_reset.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
> index 0388f9375366..0454e01e063c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> @@ -270,6 +270,12 @@ static int gen6_hw_domain_reset(struct intel_gt *gt, u32 hw_domain_mask)
>         struct intel_uncore *uncore = gt->uncore;
>         int err;
>  
> +       if (!i915_modparams.reset) {
> +               DRM_DEBUG_DRIVER("Skipping 0x%08x engines reset\n",
> +                                hw_domain_mask);
> +               return 0;

And it should be -ENODEV. Factor that into your plans :)
-Chris