From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756442Ab0FHXVK (ORCPT ); Tue, 8 Jun 2010 19:21:10 -0400 Received: from cpoproxy2-pub.bluehost.com ([67.222.39.38]:38152 "HELO cpoproxy2-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751983Ab0FHXVJ (ORCPT ); Tue, 8 Jun 2010 19:21:09 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=virtuousgeek.org; h=Received:Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=Mdp8ZoAiRbHlgxhpWaOP1EvR7Bs+8EwjeNtqEOBLkO+DTsSkenMUjAtwG5Pm8UOzsxkTKa419/TZQRsfl02tesesb94bdLyGU2RphnPeiHWjPbCdub9qsL129xO7hrL3; Date: Tue, 8 Jun 2010 16:20:03 -0700 From: Jesse Barnes To: James Simmons Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Linus Torvalds , Dave Airlie Subject: Re: [RFC] Try a bit harder to get output on the screen at panic time Message-ID: <20100608162003.58aed526@virtuousgeek.org> In-Reply-To: References: <20100409151050.74ef6dcd@virtuousgeek.org> <20100519173449.6babbdfa@virtuousgeek.org> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 75.110.194.140 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 6 Jun 2010 17:36:24 +0100 (BST) James Simmons wrote: > > > On Fri, 9 Apr 2010 15:10:50 -0700 > > Jesse Barnes wrote: > > > > > This set of 3 patches makes it a little more likely we'll get panic > > > output onto the screen even when X is running, assuming a KMS enabled > > > stack anyway. > > > > > > It gets me from a blank or very sparsely populated black screen at > > > panic time, to one including the full backtrace and panic output at > > > panic time (tested with "echo c > /proc/sysrq-trigger" from an X > > > session). > > > > > > It doesn't cover every case; for instance I think it'll fail when X has > > > disabled the display, but those cases need to be handled with separate > > > patches anyway (need to add atomic DPMS paths for instance). > > > > > > Anyway, please test these out and let me know if they work for you. > > > > Ping Linus & Dave again. Have you guys tried these? Really, it's cool. > > Is this safe with UMS and vgacon/sticon? With a oops while using vgacon > you can now touch the hardware buffer while not in vga text mode. Seems unlikely that poking VGA memory at that point would cause data corruption. There shouldn't be any other harm either, since the system is already wedged... -- Jesse Barnes, Intel Open Source Technology Center