From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: mysterious crashes on OMAP5 uevm Date: Tue, 8 Sep 2015 07:38:11 -0700 Message-ID: <20150908143810.GD4215@atomide.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Grazvydas Ignotas Cc: Nishanth Menon , "Dr. H. Nikolaus Schaller" , "linux-omap@vger.kernel.org" , Russell King - ARM Linux , "linux-arm-kernel@lists.infradead.org" List-Id: linux-omap@vger.kernel.org * Grazvydas Ignotas [150908 05:50]: > Hi, > > this is a longstanding problem I'm seeing since the very beginning, > which was around 3.12 or so (when I've first got the hardware) and it > seems 4.2 is affected by it still. Basically what happens is Xorg > randomly segfaults at some "impossible" location. I don't have the > details at the moment (could get them is needed), but from what I > examined with gdb some time ago the situation did not make any sense. > > There are 2 workarounds that I know which make the problem go away > (one is enough): > - recompile Xorg with -marm (I'm using Debian armhf so it's thumb2 by default) > - disable ARCH_MULTI_V6 in the kernel config > > Because of the above workarounds I have forgotten about it several > times, but it regularly comes back and bites again. It would look like > some missing erratum workaround, but I have all of them enabled in the > kernel. > > Does anyone know about this? Perhaps some missing erratum workaround > in the bootloader? u-boot isn't too old here (2015.07). Seems like some incorrect handling with CONFIG_CPU_V6 compiled in.. Maybe try to narrow it down by commenting out some CONFIG_CPU_V6 and __LINUX_ARM_ARCH__ = 6 ifdefs in the git grep CONFIG_CPU_V6 places ignoring uncompress and davinci code. Do you have some easy way to reproduce this issue? Regards, Tony