From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Plattner Subject: Re: role of crtcs in modesetting interfaces and possible abstraction away from userspace Date: Tue, 9 Sep 2014 23:29:52 -0700 Message-ID: <540FEFE0.6080605@nvidia.com> References: <86bnqppadp.fsf@hiro.keithp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from hqemgate14.nvidia.com (hqemgate14.nvidia.com [216.228.121.143]) by gabe.freedesktop.org (Postfix) with ESMTP id D7A67892AC for ; Tue, 9 Sep 2014 23:29:53 -0700 (PDT) In-Reply-To: <86bnqppadp.fsf@hiro.keithp.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Keith Packard , Dave Airlie , dri-devel List-Id: dri-devel@lists.freedesktop.org On 09/08/2014 11:37 PM, Keith Packard wrote: > With atomic mode setting in the kernel, I think you're probably right in > proposing to eliminate explicit CRTC allocation from that. I do think > you'll want to indicate the number of available CRTCs in the display > engine, and the number of CRTCs each monitor consumes. Do you know if > there are some of these monitors that can display lower resolution modes > with only a single CRTC? Or is the hardware so separate that you end up > always using multiple CRTCs to drive them? The one I tried definitely can; indeed it has to because the VBIOS doesn't know how to set up MST and drives the port in DP 1.1 mode. I'm sure someone will build a monitor that only turns on half of the display if you do that, but I'd be kind of surprised if someone made one that just doesn't work if you use a DP 1.1-only GPU. -- Aaron