Re: [PATCH v4] drm/i915: avoid flush_scheduled_work() usage

Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> · Fri, 19 May 2023 09:02:01 +0100

On 18/05/2023 15:44, Tetsuo Handa wrote:
Like commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue() using a
macro") says, flush_scheduled_work() is dangerous and will be forbidden.

i915 became the last flush_scheduled_work() user, but developers cannot
find time for auditing which work items does this flush_scheduled_work()
need to wait.

Therefore, for now let's start with blind/mechanical conversion within
the whole drivers/gpu/drm/i915/ directory, based on an assumption that
i915 does not need to wait for work items outside of this directory.

Link: https://lkml.kernel.org/r/87sfeita1p.fsf@xxxxxxxxx
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
Changes in v4:
   Refreshed using drm-tip.git.

Changes in v3:
   Refreshed using drm-tip.git, for commit 40053823baad ("drm/i915/display:
   move modeset probe/remove functions to intel_display_driver.c") moved
   flush_scheduled_work() from intel_display.c to intel_display_driver.c .

   Please check the comment from Daniel Vetter at
   https://lkml.kernel.org/r/ZDuntOkUeh0Eve8a@phenom.ffwll.local .

I can't help with that display code assesment but in general the 
approach with a driver global wq works for me.

Acked-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

I haven't read the patch in detail, just one thing caught my eye which 
is that we already have a workqueue named "i915" (see 
i915_workqueues_init). So I'd suggest naming the one from this patch 
"i915-global" or something. Just so it is clearer if/when debugging aids 
start firing what is what.

Regards,

Tvrtko


Changes in v2:
   Add missing alloc_workqueue() failure check.

  drivers/gpu/drm/i915/display/intel_display.c   |  2 +-
  .../drm/i915/display/intel_display_driver.c    |  2 +-
  drivers/gpu/drm/i915/display/intel_dmc.c       |  2 +-
  drivers/gpu/drm/i915/display/intel_dp.c        |  2 +-
  .../drm/i915/display/intel_dp_link_training.c  |  2 +-
  drivers/gpu/drm/i915/display/intel_drrs.c      |  2 +-
  drivers/gpu/drm/i915/display/intel_fbc.c       |  2 +-
  drivers/gpu/drm/i915/display/intel_fbdev.c     |  2 +-
  drivers/gpu/drm/i915/display/intel_hdcp.c      | 18 +++++++++---------
  drivers/gpu/drm/i915/display/intel_hotplug.c   | 12 ++++++------
  drivers/gpu/drm/i915/display/intel_opregion.c  |  2 +-
  drivers/gpu/drm/i915/display/intel_pps.c       |  2 +-
  drivers/gpu/drm/i915/display/intel_psr.c       |  6 +++---
  .../drm/i915/gt/intel_execlists_submission.c   |  4 ++--
  drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c |  8 ++++----
  drivers/gpu/drm/i915/gt/intel_gt_irq.c         |  2 +-
  drivers/gpu/drm/i915/gt/intel_gt_requests.c    | 10 +++++-----
  drivers/gpu/drm/i915/gt/intel_reset.c          |  2 +-
  drivers/gpu/drm/i915/gt/intel_rps.c            | 14 +++++++-------
  drivers/gpu/drm/i915/gt/selftest_engine_cs.c   |  2 +-
  drivers/gpu/drm/i915/i915_drv.h                |  1 +
  drivers/gpu/drm/i915/i915_module.c             |  7 +++++++
  drivers/gpu/drm/i915/i915_request.c            |  2 +-
  drivers/gpu/drm/i915/intel_wakeref.c           |  4 +++-
  drivers/gpu/drm/i915/selftests/i915_sw_fence.c |  4 +++-
  25 files changed, 64 insertions(+), 52 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 09320e14d75c..5f1ba9c908cb 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7145,7 +7145,7 @@ intel_atomic_commit_ready(struct i915_sw_fence *fence,
  				&to_i915(state->base.dev)->display.atomic_helper;
  
  			if (llist_add(&state->freed, &helper->free_list))
-				schedule_work(&helper->free_work);
+				queue_work(i915_wq, &helper->free_work);
  			break;
  		}
  	}
diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c
index 60ce10fc7205..a20a9cfaab0e 100644
--- a/drivers/gpu/drm/i915/display/intel_display_driver.c
+++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
@@ -435,7 +435,7 @@ void intel_display_driver_remove_noirq(struct drm_i915_private *i915)
  	intel_unregister_dsm_handler();
  
  	/* flush any delayed tasks or pending work */
-	flush_scheduled_work();
+	flush_workqueue(i915_wq);
  
  	intel_hdcp_component_fini(i915);
  
diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
index 8a88de67ff0a..57d015006784 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
@@ -1057,7 +1057,7 @@ void intel_dmc_init(struct drm_i915_private *i915)
  	i915->display.dmc.dmc = dmc;
  
  	drm_dbg_kms(&i915->drm, "Loading %s\n", dmc->fw_path);
-	schedule_work(&dmc->work);
+	queue_work(i915_wq, &dmc->work);
  
  	return;
  
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 4bec8cd7979f..4782bdfc7c61 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5251,7 +5251,7 @@ static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
  	spin_lock_irq(&i915->irq_lock);
  	i915->display.hotplug.event_bits |= BIT(encoder->hpd_pin);
  	spin_unlock_irq(&i915->irq_lock);
-	queue_delayed_work(system_wq, &i915->display.hotplug.hotplug_work, 0);
+	queue_delayed_work(i915_wq, &i915->display.hotplug.hotplug_work, 0);
  }
  
  static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index 0952a707358c..06859fb6f30e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -1081,7 +1081,7 @@ static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp,
  	}
  
  	/* Schedule a Hotplug Uevent to userspace to start modeset */
-	schedule_work(&intel_connector->modeset_retry_work);
+	queue_work(i915_wq, &intel_connector->modeset_retry_work);
  }
  
  /* Perform the link training on all LTTPRs and the DPRX on a link. */
diff --git a/drivers/gpu/drm/i915/display/intel_drrs.c b/drivers/gpu/drm/i915/display/intel_drrs.c
index 760e63cdc0c8..8bacb734ad78 100644
--- a/drivers/gpu/drm/i915/display/intel_drrs.c
+++ b/drivers/gpu/drm/i915/display/intel_drrs.c
@@ -111,7 +111,7 @@ static void intel_drrs_set_state(struct intel_crtc *crtc,
  
  static void intel_drrs_schedule_work(struct intel_crtc *crtc)
  {
-	mod_delayed_work(system_wq, &crtc->drrs.work, msecs_to_jiffies(1000));
+	mod_delayed_work(i915_wq, &crtc->drrs.work, msecs_to_jiffies(1000));
  }
  
  static unsigned int intel_drrs_frontbuffer_bits(const struct intel_crtc_state *crtc_state)
diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index 11bb8cf9c9d0..ba2c5b5c6e14 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -1600,7 +1600,7 @@ static void __intel_fbc_handle_fifo_underrun_irq(struct intel_fbc *fbc)
  	if (READ_ONCE(fbc->underrun_detected))
  		return;
  
-	schedule_work(&fbc->underrun_work);
+	queue_work(i915_wq, &fbc->underrun_work);
  }
  
  /**
diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
index aab1ae74a8f7..e093270b6a4c 100644
--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
@@ -689,7 +689,7 @@ void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous
  			/* Don't block our own workqueue as this can
  			 * be run in parallel with other i915.ko tasks.
  			 */
-			schedule_work(&dev_priv->display.fbdev.suspend_work);
+			queue_work(i915_wq, &dev_priv->display.fbdev.suspend_work);
  			return;
  		}
  	}
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index dd539106ee5a..d981defc8b0a 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -1001,7 +1001,7 @@ static void intel_hdcp_update_value(struct intel_connector *connector,
  	hdcp->value = value;
  	if (update_property) {
  		drm_connector_get(&connector->base);
-		schedule_work(&hdcp->prop_work);
+		queue_work(i915_wq, &hdcp->prop_work);
  	}
  }
  
@@ -2095,11 +2095,11 @@ static void intel_hdcp_check_work(struct work_struct *work)
  		return;
  
  	if (!intel_hdcp2_check_link(connector))
-		schedule_delayed_work(&hdcp->check_work,
-				      DRM_HDCP2_CHECK_PERIOD_MS);
+		queue_delayed_work(i915_wq, &hdcp->check_work,
+				   DRM_HDCP2_CHECK_PERIOD_MS);
  	else if (!intel_hdcp_check_link(connector))
-		schedule_delayed_work(&hdcp->check_work,
-				      DRM_HDCP_CHECK_PERIOD_MS);
+		queue_delayed_work(i915_wq, &hdcp->check_work,
+				   DRM_HDCP_CHECK_PERIOD_MS);
  }
  
  static int i915_hdcp_component_bind(struct device *i915_kdev,
@@ -2398,7 +2398,7 @@ int intel_hdcp_enable(struct intel_atomic_state *state,
  	}
  
  	if (!ret) {
-		schedule_delayed_work(&hdcp->check_work, check_link_interval);
+		queue_delayed_work(i915_wq, &hdcp->check_work, check_link_interval);
  		intel_hdcp_update_value(connector,
  					DRM_MODE_CONTENT_PROTECTION_ENABLED,
  					true);
@@ -2473,7 +2473,7 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state,
  		mutex_lock(&hdcp->mutex);
  		hdcp->value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
  		drm_connector_get(&connector->base);
-		schedule_work(&hdcp->prop_work);
+		queue_work(i915_wq, &hdcp->prop_work);
  		mutex_unlock(&hdcp->mutex);
  	}
  
@@ -2490,7 +2490,7 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state,
  		 */
  		if (!desired_and_not_enabled && !content_protection_type_changed) {
  			drm_connector_get(&connector->base);
-			schedule_work(&hdcp->prop_work);
+			queue_work(i915_wq, &hdcp->prop_work);
  		}
  	}
  
@@ -2609,5 +2609,5 @@ void intel_hdcp_handle_cp_irq(struct intel_connector *connector)
  	atomic_inc(&connector->hdcp.cp_irq_count);
  	wake_up_all(&connector->hdcp.cp_irq_queue);
  
-	schedule_delayed_work(&hdcp->check_work, 0);
+	queue_delayed_work(i915_wq, &hdcp->check_work, 0);
  }
diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c
index 23a5e1a875f1..8247b3e02968 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
@@ -212,7 +212,7 @@ intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
  	/* Enable polling and queue hotplug re-enabling. */
  	if (hpd_disabled) {
  		drm_kms_helper_poll_enable(&dev_priv->drm);
-		mod_delayed_work(system_wq, &dev_priv->display.hotplug.reenable_work,
+		mod_delayed_work(i915_wq, &dev_priv->display.hotplug.reenable_work,
  				 msecs_to_jiffies(HPD_STORM_REENABLE_DELAY));
  	}
  }
@@ -339,7 +339,7 @@ static void i915_digport_work_func(struct work_struct *work)
  		spin_lock_irq(&dev_priv->irq_lock);
  		dev_priv->display.hotplug.event_bits |= old_bits;
  		spin_unlock_irq(&dev_priv->irq_lock);
-		queue_delayed_work(system_wq, &dev_priv->display.hotplug.hotplug_work, 0);
+		queue_delayed_work(i915_wq, &dev_priv->display.hotplug.hotplug_work, 0);
  	}
  }
  
@@ -446,7 +446,7 @@ static void i915_hotplug_work_func(struct work_struct *work)
  		dev_priv->display.hotplug.retry_bits |= retry;
  		spin_unlock_irq(&dev_priv->irq_lock);
  
-		mod_delayed_work(system_wq, &dev_priv->display.hotplug.hotplug_work,
+		mod_delayed_work(i915_wq, &dev_priv->display.hotplug.hotplug_work,
  				 msecs_to_jiffies(HPD_RETRY_DELAY));
  	}
  }
@@ -577,7 +577,7 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
  	if (queue_dig)
  		queue_work(dev_priv->display.hotplug.dp_wq, &dev_priv->display.hotplug.dig_port_work);
  	if (queue_hp)
-		queue_delayed_work(system_wq, &dev_priv->display.hotplug.hotplug_work, 0);
+		queue_delayed_work(i915_wq, &dev_priv->display.hotplug.hotplug_work, 0);
  }
  
  /**
@@ -687,7 +687,7 @@ void intel_hpd_poll_enable(struct drm_i915_private *dev_priv)
  	 * As well, there's no issue if we race here since we always reschedule
  	 * this worker anyway
  	 */
-	schedule_work(&dev_priv->display.hotplug.poll_init_work);
+	queue_work(i915_wq, &dev_priv->display.hotplug.poll_init_work);
  }
  
  /**
@@ -715,7 +715,7 @@ void intel_hpd_poll_disable(struct drm_i915_private *dev_priv)
  		return;
  
  	WRITE_ONCE(dev_priv->display.hotplug.poll_enabled, false);
-	schedule_work(&dev_priv->display.hotplug.poll_init_work);
+	queue_work(i915_wq, &dev_priv->display.hotplug.poll_init_work);
  }
  
  void intel_hpd_init_early(struct drm_i915_private *i915)
diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
index b7973a05d022..24c0a4abcc4d 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.c
+++ b/drivers/gpu/drm/i915/display/intel_opregion.c
@@ -635,7 +635,7 @@ static void asle_work(struct work_struct *work)
  void intel_opregion_asle_intr(struct drm_i915_private *dev_priv)
  {
  	if (dev_priv->display.opregion.asle)
-		schedule_work(&dev_priv->display.opregion.asle_work);
+		queue_work(i915_wq, &dev_priv->display.opregion.asle_work);
  }
  
  #define ACPI_EV_DISPLAY_SWITCH (1<<0)
diff --git a/drivers/gpu/drm/i915/display/intel_pps.c b/drivers/gpu/drm/i915/display/intel_pps.c
index 5e7ba594e7e7..805bd0442d19 100644
--- a/drivers/gpu/drm/i915/display/intel_pps.c
+++ b/drivers/gpu/drm/i915/display/intel_pps.c
@@ -882,7 +882,7 @@ static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp)
  	 * operations.
  	 */
  	delay = msecs_to_jiffies(intel_dp->pps.panel_power_cycle_delay * 5);
-	schedule_delayed_work(&intel_dp->pps.panel_vdd_work, delay);
+	queue_delayed_work(i915_wq, &intel_dp->pps.panel_vdd_work, delay);
  }
  
  /*
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index ea0389c5f656..346ec839ab6c 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -341,7 +341,7 @@ void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir)
  		 */
  		intel_de_rmw(dev_priv, imr_reg, 0, psr_irq_psr_error_bit_get(intel_dp));
  
-		schedule_work(&intel_dp->psr.work);
+		queue_work(i915_wq, &intel_dp->psr.work);
  	}
  }
  
@@ -2453,7 +2453,7 @@ tgl_dc3co_flush_locked(struct intel_dp *intel_dp, unsigned int frontbuffer_bits,
  		return;
  
  	tgl_psr2_enable_dc3co(intel_dp);
-	mod_delayed_work(system_wq, &intel_dp->psr.dc3co_work,
+	mod_delayed_work(i915_wq, &intel_dp->psr.dc3co_work,
  			 intel_dp->psr.dc3co_exit_delay);
  }
  
@@ -2493,7 +2493,7 @@ static void _psr_flush_handle(struct intel_dp *intel_dp)
  		psr_force_hw_tracking_exit(intel_dp);
  
  		if (!intel_dp->psr.active && !intel_dp->psr.busy_frontbuffer_bits)
-			schedule_work(&intel_dp->psr.work);
+			queue_work(i915_wq, &intel_dp->psr.work);
  	}
  }
  
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 750326434677..e10d285ddb2c 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -2375,7 +2375,7 @@ static void execlists_capture(struct intel_engine_cs *engine)
  		goto err_rq;
  
  	INIT_WORK(&cap->work, execlists_capture_work);
-	schedule_work(&cap->work);
+	queue_work(i915_wq, &cap->work);
  	return;
  
  err_rq:
@@ -3680,7 +3680,7 @@ static void virtual_context_destroy(struct kref *kref)
  	 * lock, we can delegate the free of the engine to an RCU worker.
  	 */
  	INIT_RCU_WORK(&ve->rcu, rcu_virtual_context_destroy);
-	queue_rcu_work(system_wq, &ve->rcu);
+	queue_rcu_work(i915_wq, &ve->rcu);
  }
  
  static void virtual_engine_initial_hint(struct virtual_engine *ve)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
index cadfd85785b1..54aa90dff33f 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
@@ -90,8 +90,8 @@ static void pool_free_work(struct work_struct *wrk)
  		container_of(wrk, typeof(*pool), work.work);
  
  	if (pool_free_older_than(pool, HZ))
-		schedule_delayed_work(&pool->work,
-				      round_jiffies_up_relative(HZ));
+		queue_delayed_work(i915_wq, &pool->work,
+				   round_jiffies_up_relative(HZ));
  }
  
  static void pool_retire(struct i915_active *ref)
@@ -116,8 +116,8 @@ static void pool_retire(struct i915_active *ref)
  	WRITE_ONCE(node->age, jiffies ?: 1); /* 0 reserved for active nodes */
  	spin_unlock_irqrestore(&pool->lock, flags);
  
-	schedule_delayed_work(&pool->work,
-			      round_jiffies_up_relative(HZ));
+	queue_delayed_work(i915_wq, &pool->work,
+			   round_jiffies_up_relative(HZ));
  }
  
  void intel_gt_buffer_pool_mark_used(struct intel_gt_buffer_pool_node *node)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
index 8f888d36f16d..5b38e9d53e8d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
@@ -376,7 +376,7 @@ static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir)
  	if (iir & GT_RENDER_L3_PARITY_ERROR_INTERRUPT)
  		gt->i915->l3_parity.which_slice |= 1 << 0;
  
-	schedule_work(&gt->i915->l3_parity.error_work);
+	queue_work(i915_wq, &gt->i915->l3_parity.error_work);
  }
  
  void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
index 1dfd01668c79..683dc55d9191 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
@@ -116,7 +116,7 @@ void intel_engine_add_retire(struct intel_engine_cs *engine,
  	GEM_BUG_ON(intel_engine_is_virtual(engine));
  
  	if (add_retire(engine, tl))
-		schedule_work(&engine->retire_work);
+		queue_work(i915_wq, &engine->retire_work);
  }
  
  void intel_engine_init_retire(struct intel_engine_cs *engine)
@@ -207,8 +207,8 @@ static void retire_work_handler(struct work_struct *work)
  	struct intel_gt *gt =
  		container_of(work, typeof(*gt), requests.retire_work.work);
  
-	schedule_delayed_work(&gt->requests.retire_work,
-			      round_jiffies_up_relative(HZ));
+	queue_delayed_work(i915_wq, &gt->requests.retire_work,
+			   round_jiffies_up_relative(HZ));
  	intel_gt_retire_requests(gt);
  }
  
@@ -224,8 +224,8 @@ void intel_gt_park_requests(struct intel_gt *gt)
  
  void intel_gt_unpark_requests(struct intel_gt *gt)
  {
-	schedule_delayed_work(&gt->requests.retire_work,
-			      round_jiffies_up_relative(HZ));
+	queue_delayed_work(i915_wq, &gt->requests.retire_work,
+			   round_jiffies_up_relative(HZ));
  }
  
  void intel_gt_fini_requests(struct intel_gt *gt)
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index 195ff72d7a14..f4e986f4c7c9 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -1625,7 +1625,7 @@ void __intel_init_wedge(struct intel_wedge_me *w,
  	w->name = name;
  
  	INIT_DELAYED_WORK_ONSTACK(&w->work, intel_wedge_me);
-	schedule_delayed_work(&w->work, timeout);
+	queue_delayed_work(i915_wq, &w->work, timeout);
  }
  
  void __intel_fini_wedge(struct intel_wedge_me *w)
diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
index e68a99205599..9221d88118e2 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -133,12 +133,12 @@ static void rps_timer(struct timer_list *t)
  		    rps->cur_freq < rps->max_freq_softlimit) {
  			rps->pm_iir |= GEN6_PM_RP_UP_THRESHOLD;
  			rps->pm_interval = 1;
-			schedule_work(&rps->work);
+			queue_work(i915_wq, &rps->work);
  		} else if (100 * busy < rps->power.down_threshold * dt &&
  			   rps->cur_freq > rps->min_freq_softlimit) {
  			rps->pm_iir |= GEN6_PM_RP_DOWN_THRESHOLD;
  			rps->pm_interval = 1;
-			schedule_work(&rps->work);
+			queue_work(i915_wq, &rps->work);
  		} else {
  			rps->last_adj = 0;
  		}
@@ -973,7 +973,7 @@ static int rps_set_boost_freq(struct intel_rps *rps, u32 val)
  	}
  	mutex_unlock(&rps->lock);
  	if (boost)
-		schedule_work(&rps->work);
+		queue_work(i915_wq, &rps->work);
  
  	return 0;
  }
@@ -1025,7 +1025,7 @@ void intel_rps_boost(struct i915_request *rq)
  			if (!atomic_fetch_inc(&slpc->num_waiters)) {
  				GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n",
  					 rq->fence.context, rq->fence.seqno);
-				schedule_work(&slpc->boost_work);
+				queue_work(i915_wq, &slpc->boost_work);
  			}
  
  			return;
@@ -1041,7 +1041,7 @@ void intel_rps_boost(struct i915_request *rq)
  			 rq->fence.context, rq->fence.seqno);
  
  		if (READ_ONCE(rps->cur_freq) < rps->boost_freq)
-			schedule_work(&rps->work);
+			queue_work(i915_wq, &rps->work);
  
  		WRITE_ONCE(rps->boosts, rps->boosts + 1); /* debug only */
  	}
@@ -1900,7 +1900,7 @@ void gen11_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
  	gen6_gt_pm_mask_irq(gt, events);
  
  	rps->pm_iir |= events;
-	schedule_work(&rps->work);
+	queue_work(i915_wq, &rps->work);
  }
  
  void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
@@ -1917,7 +1917,7 @@ void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
  		gen6_gt_pm_mask_irq(gt, events);
  		rps->pm_iir |= events;
  
-		schedule_work(&rps->work);
+		queue_work(i915_wq, &rps->work);
  		spin_unlock(gt->irq_lock);
  	}
  
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
index 542ce6d2de19..6938b5661f72 100644
--- a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
@@ -27,7 +27,7 @@ static void perf_begin(struct intel_gt *gt)
  
  	/* Boost gpufreq to max [waitboost] and keep it fixed */
  	atomic_inc(&gt->rps.num_waiters);
-	schedule_work(&gt->rps.work);
+	queue_work(i915_wq, &gt->rps.work);
  	flush_work(&gt->rps.work);
  }
  
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 14c5338c96a6..18bafa694c35 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -931,4 +931,5 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
  #define HAS_LMEMBAR_SMEM_STOLEN(i915) (!HAS_LMEM(i915) && \
  				       GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
  
+extern struct workqueue_struct *i915_wq;
  #endif
diff --git a/drivers/gpu/drm/i915/i915_module.c b/drivers/gpu/drm/i915/i915_module.c
index 65acd7bf75d0..cf54373c33ba 100644
--- a/drivers/gpu/drm/i915/i915_module.c
+++ b/drivers/gpu/drm/i915/i915_module.c
@@ -19,6 +19,8 @@
  #include "i915_vma.h"
  #include "i915_vma_resource.h"
  
+struct workqueue_struct *i915_wq;
+
  static int i915_check_nomodeset(void)
  {
  	bool use_kms = true;
@@ -79,6 +81,9 @@ static int __init i915_init(void)
  {
  	int err, i;
  
+	i915_wq = alloc_workqueue("i915", 0, 0);
+	if (!i915_wq)
+		return -ENOMEM;
  	for (i = 0; i < ARRAY_SIZE(init_funcs); i++) {
  		err = init_funcs[i].init();
  		if (err < 0) {
@@ -86,6 +91,7 @@ static int __init i915_init(void)
  				if (init_funcs[i].exit)
  					init_funcs[i].exit();
  			}
+			destroy_workqueue(i915_wq);
  			return err;
  		} else if (err > 0) {
  			/*
@@ -113,6 +119,7 @@ static void __exit i915_exit(void)
  		if (init_funcs[i].exit)
  			init_funcs[i].exit();
  	}
+	destroy_workqueue(i915_wq);
  }
  
  module_init(i915_init);
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 630a732aaecc..c4fc7b6f740c 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -290,7 +290,7 @@ static enum hrtimer_restart __rq_watchdog_expired(struct hrtimer *hrtimer)
  
  	if (!i915_request_completed(rq)) {
  		if (llist_add(&rq->watchdog.link, &gt->watchdog.list))
-			schedule_work(&gt->watchdog.work);
+			queue_work(i915_wq, &gt->watchdog.work);
  	} else {
  		i915_request_put(rq);
  	}
diff --git a/drivers/gpu/drm/i915/intel_wakeref.c b/drivers/gpu/drm/i915/intel_wakeref.c
index dfd87d082218..46bce57c2feb 100644
--- a/drivers/gpu/drm/i915/intel_wakeref.c
+++ b/drivers/gpu/drm/i915/intel_wakeref.c
@@ -9,6 +9,8 @@
  #include "intel_runtime_pm.h"
  #include "intel_wakeref.h"
  
+extern struct workqueue_struct *i915_wq;
+
  static void rpm_get(struct intel_wakeref *wf)
  {
  	wf->wakeref = intel_runtime_pm_get(wf->rpm);
@@ -74,7 +76,7 @@ void __intel_wakeref_put_last(struct intel_wakeref *wf, unsigned long flags)
  
  	/* Assume we are not in process context and so cannot sleep. */
  	if (flags & INTEL_WAKEREF_PUT_ASYNC || !mutex_trylock(&wf->mutex)) {
-		mod_delayed_work(system_wq, &wf->work,
+		mod_delayed_work(i915_wq, &wf->work,
  				 FIELD_GET(INTEL_WAKEREF_PUT_DELAY, flags));
  		return;
  	}
diff --git a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
index daa985e5a19b..0d3396751ac5 100644
--- a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
@@ -28,6 +28,8 @@
  
  #include "../i915_selftest.h"
  
+extern struct workqueue_struct *i915_wq;
+
  static int
  fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
  {
@@ -540,7 +542,7 @@ static int test_ipc(void *arg)
  
  	ipc.value = 0;
  	INIT_WORK_ONSTACK(&ipc.work, task_ipc);
-	schedule_work(&ipc.work);
+	queue_work(i915_wq, &ipc.work);
  
  	wait_for_completion(&ipc.started);
  






