From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Agner Subject: Re: TK1 System Freeze Date: Sat, 13 Jan 2018 01:19:39 +0100 Message-ID: <7d874417cbb2067bcb4f49af000f9f03@agner.ch> References: <1511135854.13661.3.camel@toradex.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1511135854.13661.3.camel-2KBjVHiyJgBBDgjK7y7TUQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marcel Ziswiler , Thierry Reding Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org Hi Marcel, Hi Thierry, On 2017-11-20 00:57, Marcel Ziswiler wrote: > Hi there > > I lately was tasked to run some legacy Qt4e [1] application on Apalis > TK1. It should really only draw directly to the Linux frame buffer > /dev/fb0. Strangely as soon as that application is started the whole > system freezes. Running it with the VNC backend or a pure frame buffer > emulation it works just fine. So it must have something to do with the > particular way the frame buffer is done on TK1. So far no attempt in > debugging this any further bear any fruit. Whether stracing what the > application is doing nor tracing the linux kernel side of things > revealed where exactly the freeze happens. As I feared some kind of a > configuration issue on Apalis TK1 I also tried the same on Jetson TK1 > with latest stock Linux kernel 4.14. However the same freeze happens. This is still the case with 4.15-rc7. While dd is not enough to reproduce it, using a simple fbdev application such as ts_calibrate seems to be sufficient. Qt and ts_calibrate use mmap for the framebuffer. The system seems to freeze when it tries to write into the mapped area (at the memset line): https://github.com/kergoth/tslib/blob/master/tests/fbutils-linux.c#L160 Is this a known problem? Any idea? -- Stefan > > Has anybody ever seen a similar complete system freeze? Any ideas what > it may be or how we could debug this any further? > > [1] https://layers.openembedded.org/layerindex/recipe/43622/ > > Cheers > > Marcel