[Intel-gfx] [PATCH 4/7] drm/vmwgfx: Stop using plane->fb in vmw_kms_update_implicit_fb()

[Deepak Singh Rawat]

Reviewed-by: Deepak Rawat <drawat at vmware.com>

> 
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> The only caller of vmw_kms_update_implicit_fb() is the page_flip
> hook which itself gets called with the plane mutex already held.
> Hence we can look at plane->state safely. Toss in a lockdep assert
> to make the situation more clear.
> 
> Cc: Thomas Hellstrom <thellstrom at vmware.com>
> Cc: Sinclair Yeh <syeh at vmware.com>
> Cc: VMware Graphics <linux-graphics-maintainer at vmware.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index 5a824125c231..a93d290b0f35 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -2811,14 +2811,17 @@ void vmw_kms_update_implicit_fb(struct
> vmw_private *dev_priv,
>  				struct drm_crtc *crtc)
>  {
>  	struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
> +	struct drm_plane *plane = crtc->primary;
>  	struct vmw_framebuffer *vfb;
> 
> +	lockdep_assert_held(&plane->mutex);
> +
>  	mutex_lock(&dev_priv->global_kms_state_mutex);
> 
>  	if (!du->is_implicit)
>  		goto out_unlock;
> 
> -	vfb = vmw_framebuffer_to_vfb(crtc->primary->fb);
> +	vfb = vmw_framebuffer_to_vfb(plane->state->fb);
>  	WARN_ON_ONCE(dev_priv->num_implicit != 1 &&
>  		     dev_priv->implicit_fb != vfb);
> 
> --
> 2.16.1
>