Quoting Bjørn Mork (2017-10-19 11:55:18) > Bjørn Mork <bjorn@xxxxxxx> writes: > > Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > > > >> and at a guess > >> intel_iommu=igfx_off to avoid the hangs in the first place. > > > > Thanks for the tip. I'll try that > > My memory is more than a bit flakey, but this did eventually ring a > bell.,. And googling I see that I have tried that tip before without > success: > > https://bugs.freedesktop.org/show_bug.cgi?id=101288 > > > If you look at the logs attached to that bug, you'll see that the PC was > running with "intel_iommu=igfx_off" at the time of the hang: > > [ 54047.182] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.9.0-3-amd64 root=UUID=71507198-90f4-4c25-be41-efc47d2dedd1 ro intel_iommu=igfx_off IOMMU enabled?: 0 So no, not that; just a regular bug. > I believe the GPU hang reported in that bug is the same? The driver > just did not Oops while trying to reset. That oops should only happen when the context-switches are out of kilter with the breadcrumbs (i.e. the context switched away before the request was completed; that's something we try to catch during CI as the hw behaving unexpectedly). iommu is easy to suspect as we know it can introduce memory latencies that cause reordering of events, a nightmare. We've also fixed a number of races around reset, but I do not recall if they were before or after 4.9. Simplest way is grab drm-tip, apply existing userspace (hoping it hangs) and checking it no longer oopses. Reverse bisect to find the backport. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
