From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Zhang Subject: Re: [PATCH v2 12/12] JUST FOR TEST: Add one-shot trigger to update display Date: Fri, 3 Jul 2015 15:57:55 +0800 Message-ID: <55964083.60001@nvidia.com> References: <1435738915-31973-1-git-send-email-markz@nvidia.com> <1435738915-31973-13-git-send-email-markz@nvidia.com> <20150701083617.GF30960@phenom.ffwll.local> <5593AC80.10801@nvidia.com> <20150701103457.GD24055@phenom.ffwll.local> <5593E055.5050305@nvidia.com> <20150701145535.GW23343@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150701145535.GW23343-dv86pmgwkMBes7Z6vYuT8azUEOm+Xw19@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Daniel Vetter Cc: thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 07/01/2015 10:55 PM, Daniel Vetter wrote: > On Wed, Jul 01, 2015 at 08:43:01PM +0800, Mark Zhang wrote: >> On 07/01/2015 06:34 PM, Daniel Vetter wrote: [...] >>> >> >> Alright, this makes sense. I have no idea about qxl, what I have now is >> an ubuntu running on Tegra114. So I'm wondering what I suppose to do is >> installing qemu on the ubuntu? > > My suggestion is just to take the qxl code, move it to the fbdev emulation > helper, make it generic and use it. If you want you can do a > compile-tested patch on top to switch qxl over to the newly added helpers. > No need to install/run qxl itself. Just that qxl seems to have the most > complete solution for what you need. OK, thanks Daniel. I'm not quite familiar with the userspace, but I think this is the summary: - For legacy FB support, we can use the "->dirty" fops, port the qxl codes to drm_fb_helper.c, just as you described. - For atomic page flip, the one-shot can be triggered when flipping the window/plane. - How about the front buffer rendering/drawing? I mean, if a drm userspace app requests a dumb buffer then draws on it, how can we trigger the one-shot to update the display? Do we need to add an additional IOCTL to do that? Mark > -Daniel >