[Intel-gfx] [PATCH 2/7] drm/i915: Plumb the correct acquire ctx into intel_crtc_disable_noatomic()

[Jani Nikula]

On Thu, 01 Jun 2017, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> If intel_crtc_disable_noatomic() were to ever get called during resume
> e'd end up deadlocking since resume has its own acqcuire_ctx but
> intel_crtc_disable_noatomic() still tries to use the
> mode_config.acquire_ctx. Pass down the correct acquire ctx from the top.

Same here, have we seen this, or "just" theoretical?

BR,
Jani.

>
> Cc: stable at vger.kernel.org
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Fixes: e2c8b8701e2d ("drm/i915: Use atomic helpers for suspend, v2.")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 2f76a63efe8c..4e3c64ed4131 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5839,7 +5839,8 @@ static void i9xx_crtc_disable(struct intel_crtc_state *old_crtc_state,
>  		intel_update_watermarks(intel_crtc);
>  }
>  
> -static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
> +static void intel_crtc_disable_noatomic(struct drm_crtc *crtc,
> +					struct drm_modeset_acquire_ctx *ctx)
>  {
>  	struct intel_encoder *encoder;
>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> @@ -5869,7 +5870,7 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
>  		return;
>  	}
>  
> -	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
> +	state->acquire_ctx = ctx;
>  
>  	/* Everything's already locked, -EDEADLK can't happen. */
>  	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
> @@ -15257,7 +15258,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc,
>  		plane = crtc->plane;
>  		crtc->base.primary->state->visible = true;
>  		crtc->plane = !plane;
> -		intel_crtc_disable_noatomic(&crtc->base);
> +		intel_crtc_disable_noatomic(&crtc->base, ctx);
>  		crtc->plane = plane;
>  	}
>  
> @@ -15273,7 +15274,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc,
>  	/* Adjust the state of the output pipe according to whether we
>  	 * have active connectors/encoders. */
>  	if (crtc->active && !intel_crtc_has_encoders(crtc))
> -		intel_crtc_disable_noatomic(&crtc->base);
> +		intel_crtc_disable_noatomic(&crtc->base, ctx);
>  
>  	if (crtc->active || HAS_GMCH_DISPLAY(dev_priv)) {
>  		/*

-- 
Jani Nikula, Intel Open Source Technology Center