[Intel-gfx] [PATCH] drm/i915: Avoid drm_atomic_state_put(NULL) in intel_display_resume

[Ander Conselvan De Oliveira]

On Sun, 2017-01-15 at 12:58 +0000, Chris Wilson wrote:
> intel_display_resume() may be called without a atomic state to restore,
> i.e. dev_priv->modeset_reset_restore state is NULL. One such case is
> following a lid open/close event and the forced modeset in
> intel_lid_notiy().
> 
> Reported-by: Stefan Seyfried <stefan.seyfried at googlemail.com>
> Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: <drm-intel-fixes at lists.freedesktop.org> # v4.10-rc1+
> ---
>  drivers/gpu/drm/i915/intel_display.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 3dc8724df400..260bbe8881e6 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -17024,7 +17024,8 @@ void intel_display_resume(struct drm_device *dev)
>  
>  	if (ret)
>  		DRM_ERROR("Restoring old state failed with %i\n", ret);
> -	drm_atomic_state_put(state);
> +	if (state)
> +		drm_atomic_state_put(state);
>  }
>  
>  void intel_modeset_gem_init(struct drm_device *dev)


Reviewed-by: Ander Conselvan de Oliveira <conselvan2 at gmail.com>