From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Tue, 30 Jun 2015 10:04:44 +0100 Subject: Regular oops on shutdown of KVM/ARM64 machines with VGA device In-Reply-To: References: <20150629100304.GB18931@leverpostej> Message-ID: <20150630090443.GA3550@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 30, 2015 at 08:46:28AM +0100, Dirk M?ller wrote: > Hi Mark, > > > I've seen issues with prior FW versions where the ethernet controller > > was erroneously left active after ExitBootServices(), and would DMA > > braodcast packets over the kernel. That resulted in similar failures to > > what you're reporting. > > > > Can you reproduce the issue with all ethernet cables unplugged? > > not with ethernet cables unplugged, but I did ifdown on all interfaces > and was able to trigger the issue just fine. Please note it is 100% > reproducible in one sequence each and every time, which imho makes it > unlikely to be a DMA scatter issue. I see; agreed. > > You can also try enabling CONFIG_MEMTEST (and pass memtest on the > > command line) at boot time, which may happen to catch DMA in the act. > > Did not try this. Given the above it sounds like it wouldn't help anyway ;) Sorry for the noise! Mark.