Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932281AbcJNPOp (ORCPT ); Fri, 14 Oct 2016 11:14:45 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:33996 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125AbcJNPOh (ORCPT ); Fri, 14 Oct 2016 11:14:37 -0400 MIME-Version: 1.0 X-Originating-IP: [2a02:168:56b5:0:ac27:b86c:7764:9429] In-Reply-To: <20161014123914.GA10745@e106950-lin.cambridge.arm.com> References: <1476197648-24918-1-git-send-email-brian.starkey@arm.com> <6e794da8-49de-0440-ea70-272bfe47332b@codeaurora.org> <20161014123914.GA10745@e106950-lin.cambridge.arm.com> From: Daniel Vetter Date: Fri, 14 Oct 2016 16:56:25 +0200 X-Google-Sender-Auth: sQs83cRW2hhuaIdHm2YJUMYpKcY Message-ID: Subject: Re: [RFC PATCH 00/11] Introduce writeback connectors To: Brian Starkey Cc: Archit Taneja , dri-devel , Linux Kernel Mailing List , "linux-media@vger.kernel.org" , Liviu Dudau , "Clark, Rob" , Hans Verkuil , Eric Anholt , "Syrjala, Ville" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 27 On Fri, Oct 14, 2016 at 2:39 PM, Brian Starkey wrote: >> - Besides the above property, writeback hardware can have provisions >> for scaling, color space conversion and rotation. This would mean that >> we'd eventually add more writeback specific props/params in >> drm_connector/drm_connector_state. Would we be okay adding more such >> props for connectors? > > > I've wondered the same thing about bloating non-writeback connectors > with writeback-specific stuff. If it does become significant, maybe > we should subclass drm_connector and add a drm_writeback_state pointer > to drm_connector_state. No pionters needed, just embedded drm_connector_state into drm_writeback_connector_state as the "base" member. Then we can provide ready-made atomic_set/get_property functions for the aditional writeback functionality. But tbh I'd only start doing that once we have a few more. It's purely an implementation change, with no effect on userspace. And if you go with my drm_writeback_connector_init idea, it won't even be an issue for drivers. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch