From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCHv4 04/13] drm/shmobile: Restrict plane loops to only operate on legacy planes Date: Tue, 01 Apr 2014 17:27:33 +0200 Message-ID: <2592488.C8VCgpqiDA@avalon> References: <1395967478-30549-1-git-send-email-matthew.d.roper@intel.com> <20140328175250.GI22327@phenom.ffwll.local> <20140328175340.GJ22327@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [95.142.166.194]) by gabe.freedesktop.org (Postfix) with ESMTP id 843226E7E0 for ; Tue, 1 Apr 2014 10:55:56 -0700 (PDT) In-Reply-To: <20140328175340.GJ22327@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Daniel Vetter Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Hi Daniel, On Friday 28 March 2014 18:53:40 Daniel Vetter wrote: > On Fri, Mar 28, 2014 at 06:52:50PM +0100, Daniel Vetter wrote: > > On Fri, Mar 28, 2014 at 04:50:13PM +0100, Laurent Pinchart wrote: > > > On Thursday 27 March 2014 17:44:29 Matt Roper wrote: > > > > Ensure that existing driver loops over all planes do not change > > > > behavior when we begin adding new types of planes (primary and cursor) > > > > to the DRM plane list in future patches. > > > > > > > > Cc: Laurent Pinchart > > > > Signed-off-by: Matt Roper > > > > > > Acked-by: Laurent Pinchart > > > > > > I have a question though. The patch set introduces three plane types, > > > OVERLAY, PRIMARY and CURSOR. What should a driver that has no concept > > > of primary plane do ? Expose all planes as OVERLAY planes only ? > > > > It's a matter of backwards compat with old userspace. primary/cursor are > > simply ways to tell the drm core which planes to use to forward the legacy > > cursor crtc and which plane will be used for the framebuffer in setCrtc. > > > > So until we have the new atomic interface ready your driver kinda needs to > > expose at least a primary plane, otherwise there's no way to even switch > > on the crtc. > > > > But besides this backwards compat issue there's no difference and you can > > specify whatever plane you want as primary/cursor (or none if you don't > > care about old userspace). > > Well the NULL primary plane probably needs a bit of work on top of Matt's > patch series here ... It's the NULL primary plane I'm interested about, to allow a "root" plane not to span the whole display. I have no urgent need for this though, I was just curious to see if that feature was planned. -- Regards, Laurent Pinchart