[Bug 104975] Delay in skl_disable_plane() causes a system freeze

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=104975

--- Comment #4 from Ville Syrjala <ville.syrjala at linux.intel.com> ---
The fact that the system hangs is a little disappointing, but not entirely
unexpected on SKL+. Maybe we could make it fail less spectacularly if we did
the wm/ddb update more alongside the rest of the plane registers, maybe not.

As a more proper fix we could optimize the plane/pipe update some more. One of
my unfinished attempts at just that is here:
git://github.com/vsyrjala/linux.git plane_update_optimization_split_lock_alt

Another thing we could perhaps do is utilize the "lock out vblank register
latching" bit for the pipe as a backup for the atomic update fails. In theory
we could even use that instead of the vblank evade, if we decided that we never
want to override an already queued flip. But people seem to be warming up to
the idea of overriding queueud flips recently, so I think should probably keep
using the vblank evade anyway. Oh, actually I don't recall if that even locks
out every pipe/plane register, but if not then we certainly couldn't rely on it
alone.

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are on the CC list for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20180207/ef81c42d/attachment.html>