]> git.karo-electronics.de Git - karo-tx-linux.git/commit
drm/i915: Enable i915_gem_wait_for_idle() without holding struct_mutex
authorChris Wilson <chris@chris-wilson.co.uk>
Fri, 5 Aug 2016 09:14:11 +0000 (10:14 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Fri, 5 Aug 2016 09:54:37 +0000 (10:54 +0100)
commitdcff85c8443e7ad6abda897678d2fd5a950a64ad
treec987564351548f418b3d66c536c83f04fe283479
parent90f4fcd56bda1f52381bbd5034e8fb32688e779b
drm/i915: Enable i915_gem_wait_for_idle() without holding struct_mutex

The principal motivation for this was to try and eliminate the
struct_mutex from i915_gem_suspend - but we still need to hold the mutex
current for the i915_gem_context_lost(). (The issue there is that there
may be an indirect lockdep cycle between cpu_hotplug (i.e. suspend) and
struct_mutex via the stop_machine().) For the moment, enabling last
request tracking for the engine, allows us to do busyness checking and
waiting without requiring the struct_mutex - which is useful in its own
right.

As a side-effect of having a robust means for tracking engine busyness,
we can replace our other busyness heuristic, that of comparing against
the last submitted seqno. For paranoid reasons, we have a semi-ordered
check of that seqno inside the hangchecker, which we can now improve to
an ordered check of the engine's busyness (removing a locked xchg in the
process).

v2: Pass along "bool interruptible" as being unlocked we cannot rely on
i915->mm.interruptible being stable or even under our control.
v3: Replace check Ironlake i915_gpu_busy() with the common precalculated value

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470388464-28458-6-git-send-email-chris@chris-wilson.co.uk
13 files changed:
drivers/gpu/drm/i915/i915_debugfs.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/i915/i915_gem_evict.c
drivers/gpu/drm/i915/i915_gem_gtt.c
drivers/gpu/drm/i915/i915_gem_request.c
drivers/gpu/drm/i915/i915_gem_request.h
drivers/gpu/drm/i915/i915_gem_shrinker.c
drivers/gpu/drm/i915/i915_irq.c
drivers/gpu/drm/i915/intel_engine_cs.c
drivers/gpu/drm/i915/intel_pm.c
drivers/gpu/drm/i915/intel_ringbuffer.c
drivers/gpu/drm/i915/intel_ringbuffer.h