[PATCH 1/3] drm: Add drm_vblank_work_flush_all().

[PATCH 1/3] drm: Add drm_vblank_work_flush_all().

[Maarten Lankhorst]

In some cases we want to flush all vblank work, right before vblank_off
for example. Add a simple function to make this possible.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
 drivers/gpu/drm/drm_vblank_work.c | 22 ++++++++++++++++++++++
 include/drm/drm_vblank_work.h     |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/drm_vblank_work.c b/drivers/gpu/drm/drm_vblank_work.c
index 43cd5c0f4f6f..ff86f2b2e052 100644
--- a/drivers/gpu/drm/drm_vblank_work.c
+++ b/drivers/gpu/drm/drm_vblank_work.c
@@ -232,6 +232,28 @@ void drm_vblank_work_flush(struct drm_vblank_work *work)
 }
 EXPORT_SYMBOL(drm_vblank_work_flush);
 
+/**
+ * drm_vblank_work_flush_all - flush all currently pending vblank work on crtc.
+ * @crtc: crtc for which vblank work to flush
+ *
+ * Wait until all currently queued vblank work on @crtc
+ * has finished executing once.
+ */
+void drm_vblank_work_flush_all(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_vblank_crtc *vblank = &dev->vblank[drm_crtc_index(crtc)];
+
+	spin_lock_irq(&dev->event_lock);
+	wait_event_lock_irq(vblank->work_wait_queue,
+			    waitqueue_active(&vblank->work_wait_queue),
+			    dev->event_lock);
+	spin_unlock_irq(&dev->event_lock);
+
+	kthread_flush_worker(vblank->worker);
+}
+EXPORT_SYMBOL(drm_vblank_work_flush_all);
+
 /**
  * drm_vblank_work_init - initialize a vblank work item
  * @work: vblank work item
diff --git a/include/drm/drm_vblank_work.h b/include/drm/drm_vblank_work.h
index eb41d0810c4f..e04d436b7297 100644
--- a/include/drm/drm_vblank_work.h
+++ b/include/drm/drm_vblank_work.h
@@ -17,6 +17,7 @@ struct drm_crtc;
  * drm_vblank_work_init()
  * drm_vblank_work_cancel_sync()
  * drm_vblank_work_flush()
+ * drm_vblank_work_flush_all()
  */
 struct drm_vblank_work {
 	/**
@@ -67,5 +68,6 @@ void drm_vblank_work_init(struct drm_vblank_work *work, struct drm_crtc *crtc,
 			  void (*func)(struct kthread_work *work));
 bool drm_vblank_work_cancel_sync(struct drm_vblank_work *work);
 void drm_vblank_work_flush(struct drm_vblank_work *work);
+void drm_vblank_work_flush_all(struct drm_crtc *crtc);
 
 #endif /* !_DRM_VBLANK_WORK_H_ */
-- 
2.40.1

[PATCH 2/3] drm/i915: Use vblank worker to unpin old legacy cursor fb safely

[Maarten Lankhorst]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

The cursor hardware only does sync updates, and thus the hardware
will be scanning out from the old fb until the next start of vblank.
So in order to make the legacy cursor fastpath actually safe we
should not unpin the old fb until we're sure the hardware has
ceased accessing it. The simplest approach is to just use a vblank
work here to do the delayed unpin.

Not 100% sure it's a good idea to put this onto the same high
priority vblank worker as eg. our timing critical gamma updates.
But let's keep it simple for now, and it we later discover that
this is causing problems we can think about adding a lower
priority worker for such things.

This patch is slightly reworked by Maarten

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_cursor.c   | 26 +++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_display.c  |  3 +++
 .../drm/i915/display/intel_display_types.h    |  3 +++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index a515ae2831f8..e38ea7311047 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -633,6 +633,17 @@ static bool intel_cursor_format_mod_supported(struct drm_plane *_plane,
 	return format == DRM_FORMAT_ARGB8888;
 }
 
+static void intel_cursor_unpin_work(struct kthread_work *base)
+{
+	struct drm_vblank_work *work = to_drm_vblank_work(base);
+	struct intel_plane_state *plane_state =
+		container_of(work, typeof(*plane_state), unpin_work);
+	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
+
+	intel_plane_unpin_fb(plane_state);
+	intel_plane_destroy_state(&plane->base, &plane_state->uapi);
+}
+
 static int
 intel_legacy_cursor_update(struct drm_plane *_plane,
 			   struct drm_crtc *_crtc,
@@ -760,14 +771,25 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 
 	local_irq_enable();
 
-	intel_plane_unpin_fb(old_plane_state);
+	if (old_plane_state->ggtt_vma != new_plane_state->ggtt_vma) {
+		drm_vblank_work_init(&old_plane_state->unpin_work, &crtc->base,
+				     intel_cursor_unpin_work);
+
+		drm_vblank_work_schedule(&old_plane_state->unpin_work,
+					 drm_crtc_accurate_vblank_count(&crtc->base) + 1,
+					 false);
+
+		old_plane_state = NULL;
+	} else {
+		intel_plane_unpin_fb(old_plane_state);
+	}
 
 out_free:
 	if (new_crtc_state)
 		intel_crtc_destroy_state(&crtc->base, &new_crtc_state->uapi);
 	if (ret)
 		intel_plane_destroy_state(&plane->base, &new_plane_state->uapi);
-	else
+	else if (old_plane_state)
 		intel_plane_destroy_state(&plane->base, &old_plane_state->uapi);
 	return ret;
 
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 5cf162628b95..930fb471a870 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -64,6 +64,7 @@
 #include "intel_crt.h"
 #include "intel_crtc.h"
 #include "intel_crtc_state_dump.h"
+#include "intel_cursor.h"
 #include "intel_ddi.h"
 #include "intel_de.h"
 #include "intel_display_driver.h"
@@ -6752,6 +6753,8 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 			continue;
 
 		intel_crtc_disable_planes(state, crtc);
+
+		drm_vblank_work_flush_all(&crtc->base);
 	}
 
 	/* Only disable port sync and MST slaves */
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index b3e942f2eeb0..22ec3b42ceca 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -715,6 +715,9 @@ struct intel_plane_state {
 
 	struct intel_fb_view view;
 
+	/* for legacy cursor fb unpin */
+	struct drm_vblank_work unpin_work;
+
 	/* Plane pxp decryption state */
 	bool decrypt;
 
-- 
2.40.1

[PATCH 3/3] drm/i915: Use the same vblank worker for atomic unpin

[Maarten Lankhorst]

In case of legacy cursor update, the cursor VMA needs to be unpinned
only after vblank. This exceeds the lifetime of the whole atomic commit.

Any trick I attempted to keep the atomic commit alive didn't work, as
drm_atomic_helper_setup_commit() force throttles on any old commit that
wasn't cleaned up.

The only option remaining is to remove the plane from the atomic commit,
and use the same path as the legacy cursor update to clean the state
after vblank.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
 .../gpu/drm/i915/display/intel_atomic_plane.c | 28 ++++++++++++++++++-
 .../gpu/drm/i915/display/intel_atomic_plane.h |  2 ++
 drivers/gpu/drm/i915/display/intel_crtc.c     | 28 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_cursor.c   |  2 +-
 drivers/gpu/drm/i915/display/intel_cursor.h   |  3 ++
 5 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
index 06c2455bdd78..cb4153ca1867 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -42,6 +42,7 @@
 #include "i915_reg.h"
 #include "intel_atomic_plane.h"
 #include "intel_cdclk.h"
+#include "intel_cursor.h"
 #include "intel_display_rps.h"
 #include "intel_display_trace.h"
 #include "intel_display_types.h"
@@ -1163,7 +1164,21 @@ intel_cleanup_plane_fb(struct drm_plane *plane,
 
 	intel_display_rps_mark_interactive(dev_priv, state, false);
 
-	/* Should only be called after a successful intel_prepare_plane_fb()! */
+	/*
+	 * This branch can only ever be called after plane update is succesful,
+	 * the error path will not cause unpin_work to be set.
+	 */
+	if (old_plane_state->unpin_work.vblank) {
+		int i = drm_plane_index(old_plane_state->uapi.plane);
+
+		/*
+		 * Remove plane from atomic commit,
+		 * free is done from vblank worker
+		 */
+		memset(&state->base.planes[i], 0, sizeof(*state->base.planes));
+		return;
+	}
+
 	intel_plane_unpin_fb(old_plane_state);
 }
 
@@ -1176,3 +1191,14 @@ void intel_plane_helper_add(struct intel_plane *plane)
 {
 	drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
 }
+
+void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,
+					 struct intel_plane_state *new_plane_state)
+{
+	if (!old_plane_state->ggtt_vma ||
+	    old_plane_state->ggtt_vma == new_plane_state->ggtt_vma)
+		return;
+
+	drm_vblank_work_init(&old_plane_state->unpin_work, old_plane_state->uapi.crtc,
+			     intel_cursor_unpin_work);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.h b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
index 191dad0efc8e..5a897cf6fa02 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.h
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
@@ -66,5 +66,7 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state);
 void intel_plane_set_invisible(struct intel_crtc_state *crtc_state,
 			       struct intel_plane_state *plane_state);
 void intel_plane_helper_add(struct intel_plane *plane);
+void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,
+					 struct intel_plane_state *new_plane_state);
 
 #endif /* __INTEL_ATOMIC_PLANE_H__ */
diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index 1fd068e6e26c..755c40fd0ac1 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -559,6 +559,19 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
 	if (intel_crtc_needs_vblank_work(new_crtc_state))
 		intel_crtc_vblank_work_init(new_crtc_state);
 
+	if (state->base.legacy_cursor_update) {
+		struct intel_plane *plane;
+		struct intel_plane_state *old_plane_state, *new_plane_state;
+		int i;
+
+		for_each_oldnew_intel_plane_in_state(state, plane, old_plane_state,
+						     new_plane_state, i) {
+			if (old_plane_state->uapi.crtc == &crtc->base)
+				intel_plane_init_cursor_vblank_work(old_plane_state,
+								    new_plane_state);
+		}
+	}
+
 	intel_crtc_vblank_evade_scanlines(state, crtc, &min, &max, &vblank_start);
 	if (min <= 0 || max <= 0)
 		goto irq_disable;
@@ -721,6 +734,21 @@ void intel_pipe_update_end(struct intel_atomic_state *state,
 		new_crtc_state->uapi.event = NULL;
 	}
 
+	if (state->base.legacy_cursor_update) {
+		struct intel_plane *plane;
+		struct intel_plane_state *old_plane_state;
+		int i;
+
+		for_each_old_intel_plane_in_state(state, plane, old_plane_state, i) {
+			if (old_plane_state->uapi.crtc == &crtc->base &&
+			    old_plane_state->unpin_work.vblank) {
+				drm_vblank_work_schedule(&old_plane_state->unpin_work,
+							 drm_crtc_accurate_vblank_count(&crtc->base) + 1,
+							 false);
+			}
+		}
+	}
+
 	/*
 	 * Send VRR Push to terminate Vblank. If we are already in vblank
 	 * this has to be done _after_ sampling the frame counter, as
diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index e38ea7311047..1ad199a5e45d 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -633,7 +633,7 @@ static bool intel_cursor_format_mod_supported(struct drm_plane *_plane,
 	return format == DRM_FORMAT_ARGB8888;
 }
 
-static void intel_cursor_unpin_work(struct kthread_work *base)
+void intel_cursor_unpin_work(struct kthread_work *base)
 {
 	struct drm_vblank_work *work = to_drm_vblank_work(base);
 	struct intel_plane_state *plane_state =
diff --git a/drivers/gpu/drm/i915/display/intel_cursor.h b/drivers/gpu/drm/i915/display/intel_cursor.h
index ce333bf4c2d5..e2d9ec710a86 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.h
+++ b/drivers/gpu/drm/i915/display/intel_cursor.h
@@ -9,9 +9,12 @@
 enum pipe;
 struct drm_i915_private;
 struct intel_plane;
+struct kthread_work;
 
 struct intel_plane *
 intel_cursor_plane_create(struct drm_i915_private *dev_priv,
 			  enum pipe pipe);
 
+void intel_cursor_unpin_work(struct kthread_work *base);
+
 #endif
-- 
2.40.1