diff mbox series

[SRU,I/raspi,06/10] Revert "drm/vc4: kms: Remove async modeset semaphore"

Message ID 20211018155848.334053-7-juergh@canonical.com
State New
Headers show
Series HDMI output freezes under current/proposed impish kernels (LP: #1946368) | expand

Commit Message

Juerg Haefliger Oct. 18, 2021, 3:58 p.m. UTC
BugLink: https://bugs.launchpad.net/bugs/1946368

This reverts commit a28f2f0df6da70dec509b965635f0d5f71f9a9f7.

Signed-off-by: Juerg Haefliger <juergh@canonical.com>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 13 +++++++++++++
 drivers/gpu/drm/vc4/vc4_drv.h  |  2 ++
 drivers/gpu/drm/vc4/vc4_kms.c  | 24 ++++++++++++++++++++++--
 3 files changed, 37 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 0771fd91aee7..008d264cc372 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -766,6 +766,7 @@  vc4_async_page_flip_complete(struct vc4_seqno_cb *cb)
 		container_of(cb, struct vc4_async_flip_state, cb);
 	struct drm_crtc *crtc = flip_state->crtc;
 	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct drm_plane *plane = crtc->primary;
 
 	vc4_plane_async_set_fb(plane, flip_state->fb);
@@ -797,6 +798,8 @@  vc4_async_page_flip_complete(struct vc4_seqno_cb *cb)
 	}
 
 	kfree(flip_state);
+
+	up(&vc4->async_modeset);
 }
 
 /* Implements async (non-vblank-synced) page flips.
@@ -811,6 +814,7 @@  static int vc4_async_page_flip(struct drm_crtc *crtc,
 			       uint32_t flags)
 {
 	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct drm_plane *plane = crtc->primary;
 	int ret = 0;
 	struct vc4_async_flip_state *flip_state;
@@ -839,6 +843,15 @@  static int vc4_async_page_flip(struct drm_crtc *crtc,
 	flip_state->crtc = crtc;
 	flip_state->event = event;
 
+	/* Make sure all other async modesetes have landed. */
+	ret = down_interruptible(&vc4->async_modeset);
+	if (ret) {
+		drm_framebuffer_put(fb);
+		vc4_bo_dec_usecnt(bo);
+		kfree(flip_state);
+		return ret;
+	}
+
 	/* Save the current FB before it's replaced by the new one in
 	 * drm_atomic_set_fb_for_plane(). We'll need the old FB in
 	 * vc4_async_page_flip_complete() to decrement the BO usecnt and keep
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index b19da8d30225..0c3e4bce6810 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -216,6 +216,8 @@  struct vc4_dev {
 		struct work_struct reset_work;
 	} hangcheck;
 
+	struct semaphore async_modeset;
+
 	struct drm_modeset_lock ctm_state_lock;
 	struct drm_private_obj ctm_manager;
 	struct drm_private_obj hvs_channels;
diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index 24dea3acb9de..7b02bff7d939 100644
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -424,6 +424,8 @@  vc4_atomic_complete_commit(struct drm_atomic_state *state)
 		clk_request_done(core_req);
 
 	drm_atomic_state_put(state);
+
+	up(&vc4->async_modeset);
 }
 
 static void commit_work(struct work_struct *work)
@@ -481,17 +483,26 @@  static int vc4_atomic_commit(struct drm_device *dev,
 			     struct drm_atomic_state *state,
 			     bool nonblock)
 {
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	int ret;
 
 	if (state->async_update) {
-		ret = drm_atomic_helper_prepare_planes(dev, state);
+		ret = down_interruptible(&vc4->async_modeset);
 		if (ret)
 			return ret;
 
+		ret = drm_atomic_helper_prepare_planes(dev, state);
+		if (ret) {
+			up(&vc4->async_modeset);
+			return ret;
+		}
+
 		drm_atomic_helper_async_commit(dev, state);
 
 		drm_atomic_helper_cleanup_planes(dev, state);
 
+		up(&vc4->async_modeset);
+
 		return 0;
 	}
 
@@ -508,14 +519,21 @@  static int vc4_atomic_commit(struct drm_device *dev,
 
 	INIT_WORK(&state->commit_work, commit_work);
 
-	ret = drm_atomic_helper_prepare_planes(dev, state);
+	ret = down_interruptible(&vc4->async_modeset);
 	if (ret)
 		return ret;
 
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret) {
+		up(&vc4->async_modeset);
+		return ret;
+	}
+
 	if (!nonblock) {
 		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
 		if (ret) {
 			drm_atomic_helper_cleanup_planes(dev, state);
+			up(&vc4->async_modeset);
 			return ret;
 		}
 	}
@@ -995,6 +1013,8 @@  int vc4_kms_load(struct drm_device *dev)
 		vc4->load_tracker_enabled = true;
 	}
 
+	sema_init(&vc4->async_modeset, 1);
+
 	/* Set support for vblank irq fast disable, before drm_vblank_init() */
 	dev->vblank_disable_immediate = true;