On Mon, Jul 02, 2018 at 07:06:17PM +0100, Peter Maydell wrote: > On 2 July 2018 at 18:57, Guenter Roeck <li...@roeck-us.net> wrote: > > On Mon, Jul 02, 2018 at 06:10:36PM +0100, Peter Maydell wrote: > >> On 2 July 2018 at 18:05, Guenter Roeck <li...@roeck-us.net> wrote: > >> > I don't think I'll have more time available to spend on this > >> > anytime soon. If it works for you, just drop the patch. I can > >> > keep it local in my branch. My version of qemu is different anyway, > >> > after all. > >> > >> I'd kind of like to fix the bug, though. I'd just like you > >> to provide the image you're testing with... > >> > > > > Ah, but that won't help. We are dealing with a heisenbug, and me using > > a different host than you (or even a different gcc version) may be > > sufficient to make the problem disappear on your system. > > True, but we can at least rule out some differences between > your setup and mine. (For instance, your kernel config and > version and rootfs are all going to be different from what > I've been testing.) > > > The mps2 images use high resolution timers, which is likely what is > > triggering here. My working assumption is that those timers trigger at > > the wrong time because the timer is set up in periodic instead of one-time > > mode. With that, behavior is more or less random. On some systems it will > > work, on some systems it won't. Since we can not agree that setting the > > timer in periodic mode instead of one-shot mode is a problem, I don't > > really see how we can proceed. I would somehow have to prove to you that > > there is an observable problem in the first place, well beyond of what > > I already did. That might take a lot of time - much more than I would > > be able to spend on it. > > I certainly believe you that there's an observable problem. > I just disagree about your proposed fix, because I don't see > from the code why it would make any difference. So I want to > get to a point where I can run exactly the same thing you're > running on my system to have a look at what's happening. >
Please try http://server.roeck-us.net/qemu/an385/ vmlinux is plain v4.18-rc3 compiled with the provided defconfig and the provided toolchain (position independent, created with buildroot). defconfig is mps2_defconfig+CONFIG_BLK_DEV_INITRD=y. Older kernels work as well (I tested as far back as 4.9.y), with the same configuration. qemu is from the master-local branch in my repository, built with https://github.com/groeck/linux-build-test/blob/master/qemu/buildall.sh. The boot wrapper was generated from https://github.com/groeck/linux-build-test/tree/master/rootfs/arm/arm-m3-bootwrapper/. run.sh should boot the system into a shell (at least it does for me). Guenter
