Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753386Ab1DEOmh (ORCPT ); Tue, 5 Apr 2011 10:42:37 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:44168 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753303Ab1DEOmg (ORCPT ); Tue, 5 Apr 2011 10:42:36 -0400 MIME-Version: 1.0 In-Reply-To: References: <1301395589-8121-1-git-send-email-chris@chris-wilson.co.uk> <20110401114429.GA3526@viiv.ffwll.ch> From: Linus Torvalds Date: Tue, 5 Apr 2011 07:42:14 -0700 Message-ID: Subject: Re: [Intel-gfx] [PATCH] drm/i915: Disable all outputs early, before KMS takeover To: Chris Wilson , Keith Packard Cc: Tomas Winkler , Pekka Enberg , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Daniel Vetter Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2502 Lines: 55 On Tue, Apr 5, 2011 at 3:30 AM, Chris Wilson wrote: > On Tue, 5 Apr 2011 13:21:08 +0300, Tomas Winkler wrote: >> On Fri, Apr 1, 2011 at 2:51 PM, Pekka Enberg wrote: >> > Unfortunately I get a blank screen with after boot: >> > Nacked-by: Pekka Enberg > > But until you can tell me where it explodes on your system, we fix > issues on several other machines... NO. Chris, you need to understand the issue of "NO REGRESSIONS". It's a very simple rule: it DOES NOT MATTER ONE WHIT how many machines you fix. You never ever regress. Patches that cause regressions are reverted. There are multiple reasons for that rule, but the basic one ends up being very simple: you only _think_ you fix more machines than you break. Why? Because the people who test out your patches are the "active" people - and often predominantly the active people who have problems. In contrast, the people for whom things already work aren't even testing your patches in the first place. Then, six months later, when they update to a new Fedora version, things suddenly don't work for them, and it turns out that yes, you fixed ten active testers, but you broke a thousand random people. So even _one_ person saying "this is a regression" is a total blocker. Really. It's that simple. YOU NEVER EVER BREAK WORKING MACHINES. Seriously. We had this for years in ACPI-land and with suspend/resume with "one step forward, two steps back", and nobody ever knew if we were doing any real progress at all, because machines that had working suspend/resume one kernel version would be broken again the next. There was no real pattern of improvement, there was just a random pattern of "things get fixed on one machine, and break on another". We introduced the "no regressions" rule, and things got seriously better. Suddenly things started getting _reliably_ better. The whole situation with i915 has been pretty damn random lately, and you really really need to understand that this is simply not how it's done. Your cavalier attitude ("but it fixes things for others") is absolutely not acceptable. Keith Cc'd, because that patch had better not show up in my tree. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/