Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbbF2Jmg (ORCPT ); Mon, 29 Jun 2015 05:42:36 -0400 Received: from mail.skyhub.de ([78.46.96.112]:59528 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752983AbbF2Jmf (ORCPT ); Mon, 29 Jun 2015 05:42:35 -0400 Date: Mon, 29 Jun 2015 11:42:16 +0200 From: Borislav Petkov To: Daniel Vetter Cc: "Luck, Tony" , "Wang, Rui Y" , Dave Airlie , "Clark, Rob" , "Roper, Matthew D" , "Chen, Gong" , Linux Kernel Mailing List Subject: Re: drm/mgag200: doesn't work in panic context Message-ID: <20150629094215.GD12383@pd.tnic> References: <1435305314-14337-1-git-send-email-rui.y.wang@intel.com> <3908561D78D1C84285E8C5FCA982C28F32AA062A@ORSMSX114.amr.corp.intel.com> <20150627141237.GE26543@pd.tnic> <20150629080914.GB12383@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1511 Lines: 39 On Mon, Jun 29, 2015 at 11:25:17AM +0200, Daniel Vetter wrote: > As long as the display is up and running we should have a fair stab at > showing the oops Yeah, that has the same problem as all the other methods for showing oops - *if* it is still healthly. Like, for example, trying to catch an oops in networking with netconsole :) > - it's just that no one has seriously bothered with the necessary > infastructure, automated testing (it won't work otherwise) and driver > work. Right. > drm_fb_helper_panic isn't the only panic handler - fbdev/fbcon have > their own. They interfere, and fbdev blissfully assumes that it can > call almost any driver hook from hardirq context. Which means you'd > also need to consolidate the various hand-rolled (in drivers instead > of the fbdev helper) bits to offload fbdev callbacks to workers and > make sure we don't go boom in panics in there either. Hmmm, this would mean to go and tell them through the panic notifier to not do anything "risky" anymore. Perhaps even stop them from doing regular tasks which could become risky in the case of panic. I guess this would mean, we should be doing the same in other subsystems too. Hmm. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- 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/