drm/msm: Enable clocks during enable/disable_vblank() callbacks
AHB clock should be enabled before accessing registers during
enable/disable_vblank(). Since these 2 callbacks are called in
atomic context while clk_prepare may cause thread sleep, a work
is scheduled to control vblanks.
v2: fixup spinlock initialization
Signed-off-by: Hai Li <hali@codeaurora.org>
[add comment about cancel_work_sync() before drm_irq_uninstall()]
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 39ce192..0339c5d 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -116,6 +116,65 @@
return val;
}
+struct vblank_event {
+ struct list_head node;
+ int crtc_id;
+ bool enable;
+};
+
+static void vblank_ctrl_worker(struct work_struct *work)
+{
+ struct msm_vblank_ctrl *vbl_ctrl = container_of(work,
+ struct msm_vblank_ctrl, work);
+ struct msm_drm_private *priv = container_of(vbl_ctrl,
+ struct msm_drm_private, vblank_ctrl);
+ struct msm_kms *kms = priv->kms;
+ struct vblank_event *vbl_ev, *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vbl_ctrl->lock, flags);
+ list_for_each_entry_safe(vbl_ev, tmp, &vbl_ctrl->event_list, node) {
+ list_del(&vbl_ev->node);
+ spin_unlock_irqrestore(&vbl_ctrl->lock, flags);
+
+ if (vbl_ev->enable)
+ kms->funcs->enable_vblank(kms,
+ priv->crtcs[vbl_ev->crtc_id]);
+ else
+ kms->funcs->disable_vblank(kms,
+ priv->crtcs[vbl_ev->crtc_id]);
+
+ kfree(vbl_ev);
+
+ spin_lock_irqsave(&vbl_ctrl->lock, flags);
+ }
+
+ spin_unlock_irqrestore(&vbl_ctrl->lock, flags);
+}
+
+static int vblank_ctrl_queue_work(struct msm_drm_private *priv,
+ int crtc_id, bool enable)
+{
+ struct msm_vblank_ctrl *vbl_ctrl = &priv->vblank_ctrl;
+ struct vblank_event *vbl_ev;
+ unsigned long flags;
+
+ vbl_ev = kzalloc(sizeof(*vbl_ev), GFP_ATOMIC);
+ if (!vbl_ev)
+ return -ENOMEM;
+
+ vbl_ev->crtc_id = crtc_id;
+ vbl_ev->enable = enable;
+
+ spin_lock_irqsave(&vbl_ctrl->lock, flags);
+ list_add_tail(&vbl_ev->node, &vbl_ctrl->event_list);
+ spin_unlock_irqrestore(&vbl_ctrl->lock, flags);
+
+ queue_work(priv->wq, &vbl_ctrl->work);
+
+ return 0;
+}
+
/*
* DRM operations:
*/
@@ -125,6 +184,18 @@
struct msm_drm_private *priv = dev->dev_private;
struct msm_kms *kms = priv->kms;
struct msm_gpu *gpu = priv->gpu;
+ struct msm_vblank_ctrl *vbl_ctrl = &priv->vblank_ctrl;
+ struct vblank_event *vbl_ev, *tmp;
+
+ /* We must cancel and cleanup any pending vblank enable/disable
+ * work before drm_irq_uninstall() to avoid work re-enabling an
+ * irq after uninstall has disabled it.
+ */
+ cancel_work_sync(&vbl_ctrl->work);
+ list_for_each_entry_safe(vbl_ev, tmp, &vbl_ctrl->event_list, node) {
+ list_del(&vbl_ev->node);
+ kfree(vbl_ev);
+ }
drm_kms_helper_poll_fini(dev);
drm_mode_config_cleanup(dev);
@@ -282,6 +353,9 @@
INIT_LIST_HEAD(&priv->inactive_list);
INIT_LIST_HEAD(&priv->fence_cbs);
+ INIT_LIST_HEAD(&priv->vblank_ctrl.event_list);
+ INIT_WORK(&priv->vblank_ctrl.work, vblank_ctrl_worker);
+ spin_lock_init(&priv->vblank_ctrl.lock);
drm_mode_config_init(dev);
@@ -464,7 +538,7 @@
if (!kms)
return -ENXIO;
DBG("dev=%p, crtc=%d", dev, crtc_id);
- return kms->funcs->enable_vblank(kms, priv->crtcs[crtc_id]);
+ return vblank_ctrl_queue_work(priv, crtc_id, true);
}
static void msm_disable_vblank(struct drm_device *dev, int crtc_id)
@@ -474,7 +548,7 @@
if (!kms)
return;
DBG("dev=%p, crtc=%d", dev, crtc_id);
- kms->funcs->disable_vblank(kms, priv->crtcs[crtc_id]);
+ vblank_ctrl_queue_work(priv, crtc_id, false);
}
/*