[PATCH v7 07/17] drm/panfrost: Stop all jobs before commencing device teardown

[Adrián Larumbe]

We should make sure there are no inflight jobs at the time we finish driver
structures and synchronise their IRQs, and even more so by the time clocks
and power domains are disabled.

To that end, stop submissions from existing scheduler entities and force HW
to stop all running jobs.

Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/panfrost/panfrost_device.c |  2 +
 drivers/gpu/drm/panfrost/panfrost_job.c    | 71 ++++++++++++++++++------------
 drivers/gpu/drm/panfrost/panfrost_job.h    |  1 +
 3 files changed, 46 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
index 9549ddb7854a..9e02fb5f73c8 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.c
+++ b/drivers/gpu/drm/panfrost/panfrost_device.c
@@ -341,6 +341,8 @@ void panfrost_device_fini(struct panfrost_device *pfdev)
 	pm_runtime_get_sync(pfdev->base.dev);
 	pm_runtime_disable(pfdev->base.dev);
 
+	panfrost_jm_stop_sched_jobs(pfdev);
+
 	panfrost_gem_fini(pfdev);
 	panfrost_perfcnt_fini(pfdev);
 	panfrost_jm_fini(pfdev);
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index 5016d2d53da2..630298b7ea8a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -655,39 +655,12 @@ static u32 panfrost_active_slots(struct panfrost_device *pfdev,
 	return js_state & *js_state_mask;
 }
 
-static void
-panfrost_reset(struct panfrost_device *pfdev,
-	       struct drm_sched_job *bad)
+static void panfrost_stop_jobs(struct panfrost_device *pfdev)
 {
 	u32 js_state, js_state_mask = 0xffffffff;
 	unsigned int i, j;
-	bool cookie;
 	int ret;
 
-	if (!atomic_read(&pfdev->reset.pending))
-		return;
-
-	/* Stop the schedulers.
-	 *
-	 * FIXME: We temporarily get out of the dma_fence_signalling section
-	 * because the cleanup path generate lockdep splats when taking locks
-	 * to release job resources. We should rework the code to follow this
-	 * pattern:
-	 *
-	 *	try_lock
-	 *	if (locked)
-	 *		release
-	 *	else
-	 *		schedule_work_to_release_later
-	 */
-	for (i = 0; i < NUM_JOB_SLOTS; i++)
-		drm_sched_stop(&pfdev->js->queue[i].sched, bad);
-
-	cookie = dma_fence_begin_signalling();
-
-	if (bad)
-		drm_sched_increase_karma(bad);
-
 	/* Mask job interrupts and synchronize to make sure we won't be
 	 * interrupted during our reset.
 	 */
@@ -730,6 +703,48 @@ panfrost_reset(struct panfrost_device *pfdev,
 	}
 	memset(pfdev->jobs, 0, sizeof(pfdev->jobs));
 	spin_unlock(&pfdev->js->job_lock);
+}
+
+void panfrost_jm_stop_sched_jobs(struct panfrost_device *pfdev)
+{
+	for (u32 i = 0; i < NUM_JOB_SLOTS; i++)
+		drm_sched_wqueue_stop(&pfdev->js->queue[i].sched);
+
+	panfrost_stop_jobs(pfdev);
+}
+
+static void
+panfrost_reset(struct panfrost_device *pfdev,
+	       struct drm_sched_job *bad)
+{
+	unsigned int i;
+	bool cookie;
+
+	if (!atomic_read(&pfdev->reset.pending))
+		return;
+
+	/* Stop the schedulers.
+	 *
+	 * FIXME: We temporarily get out of the dma_fence_signalling section
+	 * because the cleanup path generate lockdep splats when taking locks
+	 * to release job resources. We should rework the code to follow this
+	 * pattern:
+	 *
+	 *	try_lock
+	 *	if (locked)
+	 *		release
+	 *	else
+	 *		schedule_work_to_release_later
+	 */
+	for (i = 0; i < NUM_JOB_SLOTS; i++)
+		drm_sched_stop(&pfdev->js->queue[i].sched, bad);
+
+	cookie = dma_fence_begin_signalling();
+
+	if (bad)
+		drm_sched_increase_karma(bad);
+
+	panfrost_stop_jobs(pfdev);
 
 	/* Proceed with reset now. */
 	panfrost_device_reset(pfdev, false);
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h
index 3e3b9717838f..dc9d3c9dc67b 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.h
+++ b/drivers/gpu/drm/panfrost/panfrost_job.h
@@ -73,6 +73,7 @@ int panfrost_jm_is_idle(struct panfrost_device *pfdev);
 int panfrost_job_get_slot(struct panfrost_job *job);
 int panfrost_job_push(struct panfrost_job *job);
 void panfrost_job_put(struct panfrost_job *job);
+void panfrost_jm_stop_sched_jobs(struct panfrost_device *pfdev);
 
 #ifdef CONFIG_DEBUG_FS
 void panfrost_sched_debugfs_init(struct drm_minor *minor);

-- 
2.55.0