From f351d087d8329a08eca9e69872c3906c139e1f11 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 16 May 2018 19:33:49 +0100 Subject: [PATCH] drm/i915: Only sync tasklets once for recursive reset preparation When setting up reset, we may need to recursively prepare an engine. In which case we should only synchronously flush the tasklets on the outer most call, the inner calls will then be inside an atomic section where the tasklet will never be run (and so the sync will never complete). Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20180516183355.10553-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem.h | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 0dc369a9ec4d..982393907b80 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3036,7 +3036,7 @@ i915_gem_reset_prepare_engine(struct intel_engine_cs *engine) * Turning off the execlists->tasklet until the reset is over * prevents the race. */ - tasklet_disable(&engine->execlists.tasklet); + __tasklet_disable_sync_once(&engine->execlists.tasklet); /* * We're using worker to queue preemption requests from the tasklet in diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h index 525920404ede..5bf24cfc218c 100644 --- a/drivers/gpu/drm/i915/i915_gem.h +++ b/drivers/gpu/drm/i915/i915_gem.h @@ -26,6 +26,7 @@ #define __I915_GEM_H__ #include +#include struct drm_i915_private; @@ -72,4 +73,10 @@ struct drm_i915_private; void i915_gem_park(struct drm_i915_private *i915); void i915_gem_unpark(struct drm_i915_private *i915); +static inline void __tasklet_disable_sync_once(struct tasklet_struct *t) +{ + if (atomic_inc_return(&t->count) == 1) + tasklet_unlock_wait(t); +} + #endif /* __I915_GEM_H__ */