[Intel-gfx] [PATCH] drm/i915: Increase atomic update vblank evasion time with lockdep

[Ville Syrjälä]

On Tue, Oct 10, 2017 at 10:46:57AM +0200, Daniel Vetter wrote:
> All our mmio writes take forever with lockdep due to the constant
> lock acquire&dropping we do. Ville has some patches to only acquire
> the mmio spinlocks once instead for every single mmio, but those
> aren't ready yet.
> 
> As an interim solution just extend our budget slightly when lockdep is
> enabled, to avoid the rare and sporadic noise in CI.
> 
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103169
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103124
> References: https://bugs.freedesktop.org/show_bug.cgi?id=102403
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103020
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103019
> References: https://bugs.freedesktop.org/show_bug.cgi?id=102723
> References: https://bugs.freedesktop.org/show_bug.cgi?id=102544
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103180
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>

Acked-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_sprite.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
> index b0d6e3e28d07..65f1bffe295d 100644
> --- a/drivers/gpu/drm/i915/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/intel_sprite.c
> @@ -66,7 +66,11 @@ int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
>  			    1000 * adjusted_mode->crtc_htotal);
>  }
>  
> +#if IS_ENABLED(CONFIG_PROVE_LOCKING)
> +#define VBLANK_EVASION_TIME_US 250
> +#else
>  #define VBLANK_EVASION_TIME_US 100
> +#endif
>  
>  /**
>   * intel_pipe_update_start() - start update of a set of display registers
> -- 
> 2.14.1

-- 
Ville Syrjälä
Intel OTC