Re: [PATCH v2] drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()

["Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>]

Hi CK,

Thanks for the review.

[snip]

> >  static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc)
> >  {
> >  	unsigned long flags;
> > +	struct drm_crtc *crtc = &mtk_crtc->base;
> > +	struct mtk_drm_private *priv = crtc->dev->dev_private;
> >  
> >  	drm_crtc_handle_vblank(&mtk_crtc->base);
> >  
> > -	spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> > -	if (!mtk_crtc->config_updating && mtk_crtc-
> > >pending_needs_vblank) {
> > -		mtk_crtc_finish_page_flip(mtk_crtc);
> > -		mtk_crtc->pending_needs_vblank = false;
> > +	if (priv->data->shadow_register) {
> 
> if (!priv->data->shadow_register)
> 	return;
> 
> And this would reduce the indent.
> 

OK, I'll adjust this.

> > +		spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> > +		if (!mtk_crtc->config_updating && mtk_crtc-
> > >pending_needs_vblank) {
> > +			mtk_crtc_finish_page_flip(mtk_crtc);
> > +			mtk_crtc->pending_needs_vblank = false;
> > +		}
> > +		spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> >  	}
> > -	spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> >  }
> >  
> >  static void mtk_crtc_destroy(struct drm_crtc *crtc)
> > @@ -284,10 +288,8 @@ static void ddp_cmdq_cb(struct mbox_client
> > *cl, void *mssg)
> >  	state = to_mtk_crtc_state(mtk_crtc->base.state);
> >  
> >  	spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> > -	if (mtk_crtc->config_updating) {
> > -		spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> > +	if (mtk_crtc->config_updating)
> >  		goto ddp_cmdq_cb_out;
> > -	}
> >  
> >  	state->pending_config = false;
> >  
> > @@ -315,10 +317,15 @@ static void ddp_cmdq_cb(struct mbox_client
> > *cl, void *mssg)
> >  		mtk_crtc->pending_async_planes = false;
> >  	}
> >  
> > -	spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> > -
> >  ddp_cmdq_cb_out:
> >  
> > +	if (mtk_crtc->pending_needs_vblank) {
> > +		mtk_crtc_finish_page_flip(mtk_crtc);
> > +		mtk_crtc->pending_needs_vblank = false;
> 
> In mtk_crtc_update_config(), after mbox_client_txdone() and before
> mtk_crtc->config_updating = false;
> cmdq may have finish the command and callback ddp_cmdq_cb().
> Because mtk_crtc->config_updating is true, so this page flip would be
> skipped.
> But if there is no next mtk_crtc_update_config() exist, this page
> flip would never happen.
> This may cause some deadlock.
> 

OK, I'll move the mtk_crtc->config_updating = false; earlier than 
mbox_client_txdone() to avoid skipping the page flip.

Regards,
Jason-JH.Lin

> Regards,
> CK