From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:46895 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754950AbaF3Itr (ORCPT ); Mon, 30 Jun 2014 04:49:47 -0400 Date: Mon, 30 Jun 2014 09:49:18 +0100 From: Russell King - ARM Linux To: Jean-Francois Moine Cc: Andrew Lunn , linux-ide@vger.kernel.org, Alessandro Zummo , alsa-devel@alsa-project.org, Bryan Wu , Jason Cooper , rtc-linux@googlegroups.com, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Daniel Lezcano , Sebastian Hesselbarth , Kishon Vijay Abraham I , Tejun Heo , Wim Van Sebroeck , Mark Brown , Richard Purdie , linux-pci@vger.kernel.org, Gregory Clement , Zhang Rui , Bjorn Helgaas , linux-leds@vger.kernel.org, linux-watchdog@vger.kernel.org Subject: Re: [alsa-devel] [PATCH 00/13] Remove mach-kirkwood and mach-dove Message-ID: <20140630084918.GS32514@n2100.arm.linux.org.uk> References: <1404075603-31838-1-git-send-email-andrew@lunn.ch> <20140629213510.GR32514@n2100.arm.linux.org.uk> <20140630091643.2df3b0fb@armhf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140630091643.2df3b0fb@armhf> Sender: linux-pci-owner@vger.kernel.org List-ID: On Mon, Jun 30, 2014 at 09:16:43AM +0200, Jean-Francois Moine wrote: > On Sun, 29 Jun 2014 22:35:11 +0100 > Russell King - ARM Linux wrote: > > > There is actually a cubox regression which has yet to be tracked down. > > Running with my kernel (which is not-DT based) runs perfectly. With > > DT, HDMI output can be unstable. > > Russell, > > What is this HDMI problem with DT? > > I am running a DT based kernel on my Cubox for more than 1 year and the > only problem I have is a random black screen at startup time, and this > black screen problem also exists with the old non-DT kernels from > SolidRun. The problem is that the picture appears for about a second, then goes black for maybe a couple of seconds, then reappears for about a second and this cycle repeats. Rebooting into the DT kernel doesn't fix it. Rebooting back into the non-DT kernel does fix it. Then if you boot back into the DT kernel it's back again. Boot back into the non-DT kernel and it's again fixed. I have compared register settings for the Si5351, LCD controllers and the TDA998x between the non-DT and DT versions, and can find no differences there. Yet, DT kernels are the only kernels which exhibit this behaviour. Non-DT kernels (which I've run continuously including many reboots) for the last two years have *never* shown this problem. I have also verified that the HDMI clock is correct. The problem occurs at both 1080p and 720p resolutions (which are the two that are used during boot - I have the kernel using 720p, and Xorg uses 1080p.) I should also point out that in both cases, it is the _same_ kernel binary (3.15) that I'm running - the DT test case just has the DT blob attached whereas the non-DT case boots without (and therefore falls back to the old platform stuff.) -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it.