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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2018-05-24 11:11:35 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2018-05-24 17:51:45 +0300 |
| commit | 09a4c02e58c1b3d9748f78242962b7f63c68477e (patch) | |
| tree | 95ae4c3efde90e325aaf7555f5bac77d8713be3f /drivers/gpu/drm/i915/i915_gem.c | |
| parent | 97c9de66ca8075871b31f4af05593e027e880e67 (diff) | |
| download | linux-09a4c02e58c1b3d9748f78242962b7f63c68477e.tar.xz | |
drm/i915: Look for an active kernel context before switching
We were not very carefully checking to see if an older request on the
engine was an earlier switch-to-kernel-context before deciding to emit a
new switch. The end result would be that we could get into a permanent
loop of trying to emit a new request to perform the switch simply to
flush the existing switch.
What we need is a means of tracking the completion of each timeline
versus the kernel context, that is to detect if a more recent request
has been submitted that would result in a switch away from the kernel
context. To realise this, we need only to look in our syncmap on the
kernel context and check that we have synchronized against all active
rings.
v2: Since all ringbuffer clients currently share the same timeline, we do
have to use the gem_context to distinguish clients.
As a bonus, include all the tracing used to debug the death inside
suspend.
v3: Test, test, test. Construct a selftest to exercise and assert the
expected behaviour that multiple switch-to-contexts do not emit
redundant requests.
Reported-by: Mika Kuoppala <mika.kuoppala@intel.com>
Fixes: a89d1f921c15 ("drm/i915: Split i915_gem_timeline into individual timelines")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180524081135.15278-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 03874b50ada9..05f44ca35a06 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3703,6 +3703,9 @@ static int wait_for_engines(struct drm_i915_private *i915) int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags) { + GEM_TRACE("flags=%x (%s)\n", + flags, flags & I915_WAIT_LOCKED ? "locked" : "unlocked"); + /* If the device is asleep, we have no requests outstanding */ if (!READ_ONCE(i915->gt.awake)) return 0; @@ -3719,6 +3722,7 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags) return err; } i915_retire_requests(i915); + GEM_BUG_ON(i915->gt.active_requests); return wait_for_engines(i915); } else { @@ -4901,6 +4905,7 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915) struct intel_engine_cs *engine; enum intel_engine_id id; + GEM_BUG_ON(i915->gt.active_requests); for_each_engine(engine, i915, id) { GEM_BUG_ON(__i915_gem_active_peek(&engine->timeline.last_request)); GEM_BUG_ON(engine->last_retired_context->gem_context != kctx); @@ -4932,6 +4937,8 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv) struct drm_device *dev = &dev_priv->drm; int ret; + GEM_TRACE("\n"); + intel_runtime_pm_get(dev_priv); intel_suspend_gt_powersave(dev_priv); |