Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753531Ab1FNTE3 (ORCPT ); Tue, 14 Jun 2011 15:04:29 -0400 Received: from mailout-de.gmx.net ([213.165.64.22]:53904 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753246Ab1FNTEZ (ORCPT ); Tue, 14 Jun 2011 15:04:25 -0400 X-Authenticated: #10250065 X-Provags-ID: V01U2FsdGVkX19FPoJtQn1Fdg0avVxTKBRIkp4VT67q2hOupHh1E3 7fGazD1xV6Joxz Message-ID: <4DF7B0B4.4060002@gmx.de> Date: Tue, 14 Jun 2011 19:04:20 +0000 From: Florian Tobias Schandinat User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20110505 Icedove/3.0.11 MIME-Version: 1.0 To: Linus Torvalds CC: Paul Mundt , linux-fbdev@vger.kernel.org, Linux Kernel Mailing List , Francis Moreau Subject: Re: Possible deadlock when suspending framebuffer References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1875 Lines: 57 Hi Linus, On 06/14/2011 06:15 PM, Linus Torvalds wrote: > Paul, fbdev people.. Comments? This was sent to me and lkml, the right > people probably didn't see it. Sounds very familiar. Indeed a quick glance at my archive revealed 2 approaches/patches dealing with similar issues http://marc.info/?l=linux-fbdev&m=129539210207429&w=2 http://marc.info/?l=linux-fbdev&m=129700789632450&w=2 I did not have time to verify that those do actually get those things right everywhere but the first one looks good and should also solve this issue I think. Regards, Florian Tobias Schandinat > > I doubt it's a big problem in practice, but.. > > Linus > > On Tue, Jun 14, 2011 at 6:10 AM, Francis Moreau wrote: >> Hello, >> >> I noticed that a possible deadlock can happen when the current frame >> buffering is being suspended and a new frambuffer device is being >> registred at the same time. >> >> When suspending the current frambuffer by doing : echo 1 >>> /sys/class/graphics/fb0/state, the kernel actually takes the >> following locks in that order: console_lock, lock_fb_info (see >> store_fbstate()). >> >> However when a new framebuffer is coming in, the lock sequence is: >> lock_fb_info (taken by do_remove_conflicting_framebuffer()), >> console_lock() (taken by unbind_console). >> >> I don't know how this should be fixed though... >> >> Thanks >> -- >> Francis >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/