[Intel-gfx] [PATCH] drm/i915: Move the unclaimed mmio detection into the powerwell for KMS

[Chris Wilson]

Quoting Chris Wilson (2017-05-04 12:55:08)
> Replace the large comment about requiring the powerwell for
> intel_uncore_arm_unclaimed_mmio_detection() by moving the arming of the
> mmio error detection into the powerwell held for modesetting. Thereby
> also accomplishing the goal of only arming the mmio detection after a
> full modeset.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>

Ping?

>  drivers/gpu/drm/i915/intel_display.c | 23 +++++++++--------------
>  1 file changed, 9 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 85b9e2f521a0..14e12e46eda5 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12912,8 +12912,16 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
>  
>         drm_atomic_helper_commit_hw_done(state);
>  
> -       if (intel_state->modeset)
> +       if (intel_state->modeset) {
> +               /* As one of the primary mmio accessors, KMS has a high
> +                * likelihood of triggering bugs in unclaimed access. After we
> +                * finish modesetting, see if an error has been flagged, and if
> +                * so enable debugging for the next modeset - and hope we catch
> +                * the culprit.
> +                */
> +               intel_uncore_arm_unclaimed_mmio_detection(dev_priv);
>                 intel_display_power_put(dev_priv, POWER_DOMAIN_MODESET);
> +       }
>  
>         mutex_lock(&dev->struct_mutex);
>         drm_atomic_helper_cleanup_planes(dev, state);
> @@ -12923,19 +12931,6 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
>  
>         drm_atomic_state_put(state);
>  
> -       /* As one of the primary mmio accessors, KMS has a high likelihood
> -        * of triggering bugs in unclaimed access. After we finish
> -        * modesetting, see if an error has been flagged, and if so
> -        * enable debugging for the next modeset - and hope we catch
> -        * the culprit.
> -        *
> -        * XXX note that we assume display power is on at this point.
> -        * This might hold true now but we need to add pm helper to check
> -        * unclaimed only when the hardware is on, as atomic commits
> -        * can happen also when the device is completely off.
> -        */
> -       intel_uncore_arm_unclaimed_mmio_detection(dev_priv);
> -
>         intel_atomic_helper_free_state(dev_priv);
>  }
>  
> -- 
> 2.11.0
>