From mboxrd@z Thu Jan  1 00:00:00 1970
From: daniel@ffwll.ch (Daniel Vetter)
Date: Mon, 30 May 2016 17:10:52 +0200
Subject: [Intel-gfx] [PATCH 15/26] drm/arc: Implement nonblocking commit
 correctly
In-Reply-To: <29c1b351-eb21-b6a8-928d-608a6081038e@linux.intel.com>
References: <1464546923-13439-1-git-send-email-daniel.vetter@ffwll.ch>
 <1464546923-13439-16-git-send-email-daniel.vetter@ffwll.ch>
 <656c6841-1070-0535-1ff0-97b75fd6f7ba@linux.intel.com>
 <20160530092422.GF27098@phenom.ffwll.local>
 <29c1b351-eb21-b6a8-928d-608a6081038e@linux.intel.com>
List-ID: <linux-snps-arc@lists.infradead.org>
Message-ID: <20160530151052.GP27098@phenom.ffwll.local>
To: linux-snps-arc@lists.infradead.org

On Mon, May 30, 2016@11:36:06AM +0200, Maarten Lankhorst wrote:
> Op 30-05-16 om 11:24 schreef Daniel Vetter:
> > On Mon, May 30, 2016@10:15:14AM +0200, Maarten Lankhorst wrote:
> >> Op 29-05-16 om 20:35 schreef Daniel Vetter:
> >>> Committing with block it is not.
> >>>
> >>> Thanks to the fixed up vblank event handling we can just use the
> >>> helper support for nonblocking commits now.
> >>>
> >>> Cc: Carlos Palminha <palminha at synopsys.com>
> >>> Cc: Alexey Brodkin <abrodkin at synopsys.com>
> >>> Cc: linux-snps-arc at lists.infradead.org
> >>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> >> This breaks page flip on arc, it uses drm_atomic_helper_page_flip.
> > How exactly does this break page_flip? Note that the commit to implement
> > generic nonblocking commit in drm_atomic_helper_commit is _before_ this
> > patch in the series.
> > -Daniel
> 
> This is patch 15/16, I found this in patch 21/26:
> 
> @@ -1147,8 +1206,11 @@ int drm_atomic_helper_commit(struct drm_device *dev,
>  {
>  	int ret;
>  
> -	if (nonblock)
> -		return -EBUSY;

Oh right, I mixed things up. Most of the prep work is for drm event
handling. We need to do that _before_ the non-blocking commit lands for
the drivers that just directly reuse drm_atomic_helper_commit, since the
nonblocking helpers will time out when drm events don't work.

But this one indeed should only happen after that commit. I'll reorder.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch