[PATCH 01/19] drm: Wire up proper acquire ctx for plane functions

[Harry Wentland]

On Wednesday, March 22, 2017 10:50:40 PM EDT Daniel Vetter wrote:
> This is just prep work to get an acquire ctx into every place where we
> call ->update_plane or ->disable_plane.
> 
> v2: Keep the hidden acquire_ctx pointers valid while transitioning.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  drivers/gpu/drm/drm_plane.c | 52
> ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 42
> insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index a22e76837065..0d04888172a7 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -457,7 +457,8 @@ static int __setplane_internal(struct drm_plane *plane,
>  			       uint32_t crtc_w, uint32_t crtc_h,
>  			       /* src_{x,y,w,h} values are 16.16 fixed point */
>  			       uint32_t src_x, uint32_t src_y,
> -			       uint32_t src_w, uint32_t src_h)
> +			       uint32_t src_w, uint32_t src_h,
> +			       struct drm_modeset_acquire_ctx *ctx)
>  {
>  	int ret = 0;
> 
> @@ -537,13 +538,26 @@ static int setplane_internal(struct drm_plane *plane,
>  			     uint32_t src_x, uint32_t src_y,
>  			     uint32_t src_w, uint32_t src_h)
>  {
> +	struct drm_modeset_acquire_ctx ctx;
>  	int ret;
> 
> -	drm_modeset_lock_all(plane->dev);
> +	drm_modeset_acquire_init(&ctx, 0);
> +retry:
> +	ret = drm_modeset_lock_all_ctx(plane->dev, &ctx);
> +	if (ret)
> +		goto fail;
> +	plane->dev->mode_config.acquire_ctx = &ctx;
>  	ret = __setplane_internal(plane, crtc, fb,
>  				  crtc_x, crtc_y, crtc_w, crtc_h,
> -				  src_x, src_y, src_w, src_h);
> -	drm_modeset_unlock_all(plane->dev);
> +				  src_x, src_y, src_w, src_h, &ctx);
> +
> +fail:
> +	if (ret == -EDEADLK) {
> +		drm_modeset_backoff(&ctx);
> +		goto retry;
> +	}
> +	drm_modeset_drop_locks(&ctx);
> +	drm_modeset_acquire_fini(&ctx);
> 
>  	return ret;
>  }
> @@ -613,11 +627,22 @@ static int drm_mode_cursor_universal(struct drm_crtc
> *crtc, int32_t crtc_x, crtc_y;
>  	uint32_t crtc_w = 0, crtc_h = 0;
>  	uint32_t src_w = 0, src_h = 0;
> +	struct drm_modeset_acquire_ctx ctx;
>  	int ret = 0;
> 
>  	BUG_ON(!crtc->cursor);
>  	WARN_ON(crtc->cursor->crtc != crtc && crtc->cursor->crtc != NULL);
> 
> +	drm_modeset_acquire_init(&ctx, 0);
> +retry:
> +	ret = drm_modeset_lock(&crtc->mutex, &ctx);
> +	if (ret)
> +		goto fail;
> +	ret = drm_modeset_lock(&crtc->cursor->mutex, &ctx);
> +	if (ret)
> +		goto fail;
> +	crtc->acquire_ctx = &ctx;
> +
>  	/*
>  	 * Obtain fb we'll be using (either new or existing) and take an extra
>  	 * reference to it if fb != null.  setplane will take care of dropping
> @@ -662,7 +687,7 @@ static int drm_mode_cursor_universal(struct drm_crtc
> *crtc, */
>  	ret = __setplane_internal(crtc->cursor, crtc, fb,
>  				crtc_x, crtc_y, crtc_w, crtc_h,
> -				0, 0, src_w, src_h);
> +				0, 0, src_w, src_h, &ctx);
> 
>  	/* Update successful; save new cursor position, if necessary */
>  	if (ret == 0 && req->flags & DRM_MODE_CURSOR_MOVE) {
> @@ -670,6 +695,15 @@ static int drm_mode_cursor_universal(struct drm_crtc
> *crtc, crtc->cursor_y = req->y;
>  	}
> 
> +fail:
> +	if (ret == -EDEADLK) {
> +		drm_modeset_backoff(&ctx);
> +		goto retry;
> +	}
> +
> +	drm_modeset_drop_locks(&ctx);
> +	drm_modeset_acquire_fini(&ctx);
> +
>  	return ret;
>  }
> 
> @@ -696,12 +730,10 @@ static int drm_mode_cursor_common(struct drm_device
> *dev, * If this crtc has a universal cursor plane, call that plane's update
> * handler rather than using legacy cursor handlers.
>  	 */
> -	drm_modeset_lock_crtc(crtc, crtc->cursor);
> -	if (crtc->cursor) {
> -		ret = drm_mode_cursor_universal(crtc, req, file_priv);
> -		goto out;
> -	}
> +	if (crtc->cursor)
> +		return drm_mode_cursor_universal(crtc, req, file_priv);
> 
> +	drm_modeset_lock_crtc(crtc, crtc->cursor);

Why are you moving the lock? Shouldn't it still be covering the call to 
drm_mode_cursor_universal?

Harry


>  	if (req->flags & DRM_MODE_CURSOR_BO) {
>  		if (!crtc->funcs->cursor_set && !crtc->funcs->cursor_set2) {
>  			ret = -ENXIO;