From: Chris Wilson Date: Tue, 15 Nov 2016 16:46:20 +0000 (+0000) Subject: drm/i915: Be more careful to drop the GT wakeref X-Git-Tag: Ubuntu-5.4-5.4.0-11.14~8846^2~21^2~7 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=4302055b29cbc8566aaa5eb7f594ea9cc78ebf41;p=mirror_ubuntu-focal-kernel.git drm/i915: Be more careful to drop the GT wakeref Since we can retire requests from multiple paths, we cannot assume that i915_gem_retire_requests() is the sole path on which we can transition to gt.active_requests == 0. A consequence of this is that we would skip the function if we had already retired all the requests and not scheduled the idle worker. This is fallout from changing the routine from considering active_engines (for which it was the only consumer) to active_requests. v2: Move kicking the idle working to i915_gem_request_retire() otherwise we could postpone the idle callback everytime we called retire_requests even though we did no work. v3: We only need to move the idle work kicking! v4: Drop the BUG_ON(!awake) as we may be called from the shrinker in the middle of constructing a request before we have marked the device awake. v5: Add a BUG_ON() for active_requests underflow upon retirement (Joonas) Fixes: 28176ef4cfa5 ("drm/i915: Reserve space in the global seqno during request allocation") Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20161115164620.17185-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen --- diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index b9b5253cf3cd..db2cac7f5d43 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -201,6 +201,7 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request) lockdep_assert_held(&request->i915->drm.struct_mutex); GEM_BUG_ON(!i915_gem_request_completed(request)); + GEM_BUG_ON(!request->i915->gt.active_requests); trace_i915_gem_request_retire(request); @@ -218,7 +219,12 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request) */ list_del(&request->ring_link); request->ring->last_retired_head = request->postfix; - request->i915->gt.active_requests--; + if (!--request->i915->gt.active_requests) { + GEM_BUG_ON(!request->i915->gt.awake); + mod_delayed_work(request->i915->wq, + &request->i915->gt.idle_work, + msecs_to_jiffies(100)); + } /* Walk through the active list, calling retire on each. This allows * objects to track their GPU activity and mark themselves as idle @@ -763,6 +769,8 @@ static void i915_gem_mark_busy(const struct intel_engine_cs *engine) if (dev_priv->gt.awake) return; + GEM_BUG_ON(!dev_priv->gt.active_requests); + intel_runtime_pm_get_noresume(dev_priv); dev_priv->gt.awake = true; @@ -1146,13 +1154,6 @@ void i915_gem_retire_requests(struct drm_i915_private *dev_priv) if (!dev_priv->gt.active_requests) return; - GEM_BUG_ON(!dev_priv->gt.awake); - for_each_engine(engine, dev_priv, id) engine_retire_requests(engine); - - if (!dev_priv->gt.active_requests) - mod_delayed_work(dev_priv->wq, - &dev_priv->gt.idle_work, - msecs_to_jiffies(100)); }