drm: atmel-hlcdc: support asynchronous atomic commit operations

drm_atomic_helper_commit() does not support asynchronous commits.
Replace it by a specific commit function supporting these kind of requests.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Nicolas Ferre <nicolas.ferre@atmel.com>

1 files changed, 93 insertions, 1 deletions

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 8ab4318e57a1..67b139174e7b 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -427,11 +427,102 @@ static void atmel_hlcdc_fb_output_poll_changed(struct drm_device *dev)
         }
 }
 
+struct atmel_hlcdc_dc_commit {
+        struct work_struct work;
+        struct drm_device *dev;
+        struct drm_atomic_state *state;
+};
+
+static void
+atmel_hlcdc_dc_atomic_complete(struct atmel_hlcdc_dc_commit *commit)
+{
+        struct drm_device *dev = commit->dev;
+        struct atmel_hlcdc_dc *dc = dev->dev_private;
+        struct drm_atomic_state *old_state = commit->state;
+
+        /* Apply the atomic update. */
+        drm_atomic_helper_commit_modeset_disables(dev, old_state);
+        drm_atomic_helper_commit_planes(dev, old_state, false);
+        drm_atomic_helper_commit_modeset_enables(dev, old_state);
+
+        drm_atomic_helper_wait_for_vblanks(dev, old_state);
+
+        drm_atomic_helper_cleanup_planes(dev, old_state);
+
+        drm_atomic_state_free(old_state);
+
+        /* Complete the commit, wake up any waiter. */
+        spin_lock(&dc->commit.wait.lock);
+        dc->commit.pending = false;
+        wake_up_all_locked(&dc->commit.wait);
+        spin_unlock(&dc->commit.wait.lock);
+
+        kfree(commit);
+}
+
+static void atmel_hlcdc_dc_atomic_work(struct work_struct *work)
+{
+        struct atmel_hlcdc_dc_commit *commit =
+                container_of(work, struct atmel_hlcdc_dc_commit, work);
+
+        atmel_hlcdc_dc_atomic_complete(commit);
+}
+
+static int atmel_hlcdc_dc_atomic_commit(struct drm_device *dev,
+                                        struct drm_atomic_state *state,
+                                        bool async)
+{
+        struct atmel_hlcdc_dc *dc = dev->dev_private;
+        struct atmel_hlcdc_dc_commit *commit;
+        int ret;
+
+        ret = drm_atomic_helper_prepare_planes(dev, state);
+        if (ret)
+                return ret;
+
+        /* Allocate the commit object. */
+        commit = kzalloc(sizeof(*commit), GFP_KERNEL);
+        if (!commit) {
+                ret = -ENOMEM;
+                goto error;
+        }
+
+        INIT_WORK(&commit->work, atmel_hlcdc_dc_atomic_work);
+        commit->dev = dev;
+        commit->state = state;
+
+        spin_lock(&dc->commit.wait.lock);
+        ret = wait_event_interruptible_locked(dc->commit.wait,
+                                              !dc->commit.pending);
+        if (ret == 0)
+                dc->commit.pending = true;
+        spin_unlock(&dc->commit.wait.lock);
+
+        if (ret) {
+                kfree(commit);
+                goto error;
+        }
+
+        /* Swap the state, this is the point of no return. */
+        drm_atomic_helper_swap_state(dev, state);
+
+        if (async)
+                queue_work(dc->wq, &commit->work);
+        else
+                atmel_hlcdc_dc_atomic_complete(commit);
+
+        return 0;
+
+error:
+        drm_atomic_helper_cleanup_planes(dev, state);
+        return ret;
+}
+
 static const struct drm_mode_config_funcs mode_config_funcs = {
         .fb_create = atmel_hlcdc_fb_create,
         .output_poll_changed = atmel_hlcdc_fb_output_poll_changed,
         .atomic_check = drm_atomic_helper_check,
-        .atomic_commit = drm_atomic_helper_commit,
+        .atomic_commit = atmel_hlcdc_dc_atomic_commit,
 };
 
 static int atmel_hlcdc_dc_modeset_init(struct drm_device *dev)
@@ -509,6 +600,7 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
         if (!dc->wq)
                 return -ENOMEM;
 
+        init_waitqueue_head(&dc->commit.wait);
         dc->desc = match->data;
         dc->hlcdc = dev_get_drvdata(dev->dev->parent);
         dev->dev_private = dc;