From 4aed7201ccd13f1431b35423bb84d3159b85ee0f Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 12 Mar 2020 11:53:07 +0000
Subject: drm/i915/gt: Wait for RCUs frees before asserting idle on unload
Git-commit: 22ca8a452e5791c9721e1ba61e95651fc00a9e4d
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
During driver unload, we have many asserts that we have released our
bookkeeping structs and are idle. In some cases, these struct are
protected by RCU and we do not release them until after an RCU grace
period.
Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: 130a95e9098e ("drm/i915/gem: Consolidate ctx->engines[] release")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200312115307.16460-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
drivers/gpu/drm/i915/gt/intel_gt.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 895cedc3f023..026999b34abd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -903,6 +903,7 @@ void i915_gem_init__contexts(struct drm_i915_private *i915)
void i915_gem_driver_release__contexts(struct drm_i915_private *i915)
{
flush_work(&i915->gem.contexts.free_work);
+ rcu_barrier(); /* and flush the left over RCU frees */
}
static int gem_context_register(struct i915_gem_context *ctx,
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index 3dea8881e915..d09f7596cb98 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -667,6 +667,9 @@ void intel_gt_driver_release(struct intel_gt *gt)
void intel_gt_driver_late_release(struct intel_gt *gt)
{
+ /* We need to wait for inflight RCU frees to release their grip */
+ rcu_barrier();
+
intel_uc_driver_late_release(>->uc);
intel_gt_fini_requests(gt);
intel_gt_fini_reset(gt);
--
2.28.0