From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751726AbaFVPLP (ORCPT ); Sun, 22 Jun 2014 11:11:15 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:38187 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751364AbaFVPLN (ORCPT ); Sun, 22 Jun 2014 11:11:13 -0400 Date: Sun, 22 Jun 2014 17:11:11 +0200 From: Pavel Machek To: Chris Wilson , Daniel Vetter , "Rafael J. Wysocki" , kernel list , intel-gfx Subject: regression: 3.16, i915: less colors in X?, caused by 773875bfb6737982903c42d1ee88cf60af80089c Message-ID: <20140622151111.GA4090@amd.pavel.ucw.cz> References: <20140607120614.GB5309@amd.pavel.ucw.cz> <20140607231124.GA3611@amd.pavel.ucw.cz> <20140609102328.GA25332@amd.pavel.ucw.cz> <20140621202901.GA3840@amd.pavel.ucw.cz> <20140621210652.GA14025@nuc-i3427.alporthouse.com> <20140622142622.GA4107@amd.pavel.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140622142622.GA4107@amd.pavel.ucw.cz> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > I just test-booted 3.16-rc1, and background in X looked just wrong -- > > > very noticeable bands on the background gradient. I thought that maybe > > > it is just my eyes, but I went back to older kernel, and background is > > > ok now. > > > > > > I'm trying to figure out how to ask X what color depth it is using...? > > > > > > This is thinkpad x60 with Debian 6.0.9. > > > > > > Any ideas? > > > > That suggests that the panel dithering changed. Compare intel_reg_dumper > > output for both kernels, especially PIPE.CONF. intel_reg_dumper has so many dependencies that it is basically impossible to get working :-(. Anyway, this seems to be the problem; if I revert it, my colors are back. commit 773875bfb6737982903c42d1ee88cf60af80089c Author: Daniel Vetter Date: Mon Jan 27 10:00:30 2014 +0100 drm/i915: Don't set the 8to6 dither flag when not scaling Apparently we really only need this when the pfit is enabled, at least I couldn't dicern any difference here. Furthermore the hacks we have to reconstruct this bit is a bit glaring, and probably only works because we can't move the lvds port to any other pipe than pipe B on gen2/3. So let's just rip this out. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77137 (the LVDS WARNING log, not the main "VGA can't be turned on" issue). Signed-off-by: Daniel Vetter Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html