I've cc'ed some folks in hopes to get this resolved upstream. Either way, 4.1's EoL was previously moved to about 6 months from now, so hopefully we'll have more than enough time to get this resolved. On Sat, Nov 11, 2017 at 10:13:55PM +0000, Tuncer Ayaz wrote: >The predicament I'm in on my machines is that ever since drm-intel has >implemented atomic modesetting, there's a list regressions caused by >those fundamental architecture changes and the code churn it implied. >This means 4.1 is (from what I can tell) the last kernel before atomic >modesetting was added and the only kernel free of all those issues >which necessitate trying out various combinations of flags on the >kernel cmdline. > >For instance, right now I'm trying 4.13.12 with these flags: >video=SVIDEO-1:d >i915.semaphores=1 >i915.enable_rc6=0 >i915.enable_psr=0 >intel_iommu=igfx_off > >PS: I'm kinda confused how anyone uses DMAR with VT-d when it's known >to be buggy. > >The flags seem to decrease the chances of provoking the bugs, but after a >day of running Xorg, it's possible to still hit the RCS0 GPU hangs. > >If you don't pass video=SVIDEO-1:d, then atomic's flip_done times out >on boot or exit to VT console. It's good that other people have the same >issues and have been following the bugzilla tickets, and con confirm >the results. > >I'm kinda glad I don't have a machine that's newer than Sandybridge >since that means I can use 4.1, though it's not a long-term solution, >and the plan is for the reported bugzilla tickets to be resolved at >some point, or me switching away from Intel GPUs, which might be >doable if I save money and get an AMD APU laptop next summer and >switch my desktop to a discrete GPU. > >For example: >https://bugs.freedesktop.org/show_bug.cgi?id=101237 >https://bugs.freedesktop.org/show_bug.cgi?id=103076 >https://bbs.archlinux.org/viewtopic.php?id=218581&p=3 >https://bugs.archlinux.org/task/51703 > >So, since 4.4, 4.9 and 4.12, drm-tip are still regressive, >I wanted to ask if you considered pushing back 4.1's EOL. > >Given a look at bugzilla, I have the impression that those issues will >need at least another year before they're fixed, since most of them >have been sitting there for many, many months. I suspect the Intel DRM >team doesn't have the bandwidth to address the issues in a timely >fashion while still adding upbringing for new GPUs and features >(fences, etc.). > >The generic modesetting DDX and Wayland are less susceptible to the >GPU hangs, but can be made to provoke it if tried long enough. >However, the modesetting DDX tears heavily and is about to gain atomic >modesetting in the next Xorg release, so will suffer from the same >easy GPU hang likelihood. > >Prior to SandyBridge there was zero tearing but beginning with >SandyBridge xf86-video-intel's TearFree=TRUE is the only reliable way >to fix Xorg tearing. > >I do appreciate you maintaining 4.1 so far and hate to admit that I'm >reliant on it on more than two machines, before and after Sandybridge, >exluding those machines which need a newer kernel. I also understand >how much work this is and since I'm not using Linux professionally for >a product, I can't offer compensation for your time. I can only offer >to collect and point you at a list of DRM bugs for validation of my >claims. -- Thanks, Sasha