On 13.01.2018 01:19, Stefan Agner wrote: > 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? Thierry, anybody else, any idea? This should be easily reproducible on Jetson TK1. -- 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 > -- > To unsubscribe from this list: send the line "unsubscribe linux-tegra" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
