Re: 4.1 EOL

[Jani Nikula]

Tuncer, where's your bug report? Can't find one. Please file your bug at
the fdo bugzilla.

Thanks,
Jani.

On Mon, 13 Nov 2017, alexander.levin@xxxxxxxxxxx wrote:
> 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.

-- 
Jani Nikula, Intel Open Source Technology Center