From patchwork Tue Sep 25 13:16:23 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Bader X-Patchwork-Id: 186811 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 418222C0082 for ; Tue, 25 Sep 2012 23:16:58 +1000 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TGUxY-0000gW-V3; Tue, 25 Sep 2012 13:13:56 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TGUxV-0000fv-HX for kernel-team@lists.ubuntu.com; Tue, 25 Sep 2012 13:13:53 +0000 Received: from p5b2e4cf2.dip.t-dialin.net ([91.46.76.242] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1TGUzx-00027f-2m for kernel-team@lists.ubuntu.com; Tue, 25 Sep 2012 13:16:25 +0000 From: Stefan Bader To: kernel-team@lists.ubuntu.com Subject: [Quantal RFC] Avoid using the QEMU DRM (cirrus) driver Date: Tue, 25 Sep 2012 15:16:23 +0200 Message-Id: <1348578983-16055-1-git-send-email-stefan.bader@canonical.com> X-Mailer: git-send-email 1.7.9.5 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com As stated below, there is currently a race with that driver which is not easy to remove. Also when using the drm driver + the modeset X driver, I had quite a bad time when trying to change resolution of the desktop. And it gives a different experience when running Xen and KVM (while both seem to have a cirrus VGA). For completeness I must say that at least on my desktop which does suffer from cpu exhaustion, I have still seen X crashes that look similar to the one that previously happened on startup (bug 1056080). Instead of not compiling the module (which will also need a module.ignore or an abi bump), it could be blacklisted. But I am not sure this can be done from the kernel package. Speed can often suck in both cases, but what would be other peoples thoughts? -Stefan From 88adc6f8c438e969407dfe7fa989def4d9a20980 Mon Sep 17 00:00:00 2001 From: Stefan Bader Date: Tue, 25 Sep 2012 14:56:28 +0200 Subject: [PATCH] UBUNTU: (config) Disable the QEMU drm driver When enabled, this driver will provide modeset support for the emulated cirrus card in KVM (and only KVM, not Xen). However this currently leads to boot races as grub will cause generic parts of the efifb driver to get active which the cirrus DRM driver then has to replace. By now the cirrus X driver (or unity) has been fixed not to crash on starting unity. So by disabling the driver we avoid the race and get the same experience with KVM and Xen. BugLink: http://bugs.launchpad.net/bugs/1038055 Signed-off-by: Stefan Bader --- debian.master/config/config.common.ubuntu | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/debian.master/config/config.common.ubuntu b/debian.master/config/config.common.ubuntu index 9134a9d..edba5e0 100644 --- a/debian.master/config/config.common.ubuntu +++ b/debian.master/config/config.common.ubuntu @@ -1384,7 +1384,7 @@ CONFIG_DRAGONRISE_FF=y # CONFIG_DRBD_FAULT_INJECTION is not set CONFIG_DRM=m # CONFIG_DRM_AST is not set -CONFIG_DRM_CIRRUS_QEMU=m +# CONFIG_DRM_CIRRUS_QEMU is not set CONFIG_DRM_GMA3600=y CONFIG_DRM_GMA500=m CONFIG_DRM_GMA600=y