From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Tue, 8 Sep 2015 07:38:11 -0700 Subject: mysterious crashes on OMAP5 uevm In-Reply-To: References: Message-ID: <20150908143810.GD4215@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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