Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762919AbcJaImz (ORCPT ); Mon, 31 Oct 2016 04:42:55 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:55252 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762618AbcJaImw (ORCPT ); Mon, 31 Oct 2016 04:42:52 -0400 Date: Mon, 31 Oct 2016 08:42:34 +0000 From: Russell King - ARM Linux To: Maxime Ripard Cc: Daniel Vetter , David Airlie , Thomas Petazzoni , Boris Brezillon , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Hans de Goede , Chen-Yu Tsai , Laurent Pinchart , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/5] drm/sun4i: Handle TV overscan Message-ID: <20161031084233.GS1041@n2100.armlinux.org.uk> References: <20161018092422.GJ1041@n2100.armlinux.org.uk> <20161018100349.qm2f554oiwyjwrsi@lukather> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161018100349.qm2f554oiwyjwrsi@lukather> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2356 Lines: 48 On Tue, Oct 18, 2016 at 12:03:49PM +0200, Maxime Ripard wrote: > The first one is that this overscanning should be reported by the > connector I guess? but this is really TV specific, so we need one way > to let the user tell how the image is displayed on its side, and we > cannot really autodetect it, and this needs to be done at runtime so > that we can present some shiny interface to let it select which > overscan ratio works for him/her. See xbmc... they go through a nice shiny setup which includes adjusting the visible area. From what I remember, it has pointers on each corner which you can adjust to be just visible on the screen, so xbmc knows how much overscan there is, and xbmc itself reduces down to the user set size. > The second one is that we still need to expose the reduced modes to > userspace, and not only the displayed size, so that the applications > know what they must draw on. But I guess this could be adjusted by the > core too. > > In order to work consistently, I think all planes should be adjusted > that way, so that relative coordinates are from the primary plane > origin, and not the display origin. But that could be adjusted too by > the core I guess. I'm not sure about that - we want the graphics to be visible, but that may not be appropriate for an video overlay frame. It's quite common for (eg) broadcast video to contain dead pixels or other artifacts on the right hand side, and the broadcast video expects overscan to be present. I know this because I have run my TV with overscan disabled, even for broadcast TV. > The fourth one being the major one. Every time I raised the issue on > IRC, the answer basically was "we don't care about analog", so I'm a > bit pessimistic about whether dealing with this in the core would be > accepted, hence why I chose to deal with this at the driver level. Yea, that's quite sad, "analog" has become a dirty word, but really this has nothing to do with "analog" at all - there are LCD TVs (and some monitors) out there which take HDMI signals but refuse to disable overscan no matter what you do to them if you provide them with a "broadcast" mode - so the analog excuse is very poor. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.