[Intel-gfx] [PATCH v3] drm/i915: Fix recursive calls to unmap

[Dave Airlie]

>> >
>> > The solution here is to add a new flag to the call chain which gives the
>> > routines the information they need to possibly defer actions which may
>> > cause us to recurse. A macro has been defined to replace i915_gpu_idle
>> > which defaults to the old behavior.
>> >
>> > Kudos to Chris for tracking this one down.
>>
>> So this fixes the non-VTd case, the VT-d case still hits a recursion
>> here, for posterity its below.

Okay I take that back, I got my EL6 kernel rock stable with the
correct blend of backported bits.

So ignore that backtrace, however I did get another IOMMU hang on my
upstream kernel with gem_linear_blits,

so this should be fine to merge but I'm guessing we have more
debugging to do on the VT-d cases.

Dave.