Well we can't use that directly since that code must hold
dev->event_lock already. Extract an _unlocked version.
Embarrassingly I've totally forgotten about this patch and any kind of
event-based vblank wait totally blew up, killing the kernel.
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Daniel Stone <daniels@xxxxxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
drivers/gpu/drm/drm_fops.c | 64 +++++++++++++++++++++++++++++++++++-----------
drivers/gpu/drm/drm_irq.c | 10 +++-----
include/drm/drmP.h | 4 +++
3 files changed, 56 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index e13501e3606e..eb6a02f78697 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -678,7 +678,7 @@ unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
EXPORT_SYMBOL(drm_poll);
/**
- * drm_event_reserve_init - init a DRM event and reserve space for it
+ * drm_event_reserve_init_locked - init a DRM event and reserve space for it
* @dev: DRM device
* @file_priv: DRM file private data
* @p: tracking structure for the pending event
@@ -694,24 +694,20 @@ EXPORT_SYMBOL(drm_poll);
* If callers embedded @p into a larger structure it must be allocated with
* kmalloc and @p must be the first member element.
*
+ * This is the locked version of drm_event_reserve_init() for callers which
+ * already hold dev->event_lock.
+ *
* RETURNS:
*
* 0 on success or a negative error code on failure.
*/
-int drm_event_reserve_init(struct drm_device *dev,
- struct drm_file *file_priv,
- struct drm_pending_event *p,
- struct drm_event *e)
+int drm_event_reserve_init_locked(struct drm_device *dev,
+ struct drm_file *file_priv,
+ struct drm_pending_event *p,
+ struct drm_event *e)
{
- unsigned long flags;
- int ret = 0;
-
- spin_lock_irqsave(&dev->event_lock, flags);
-
- if (file_priv->event_space < e->length) {
- ret = -ENOMEM;
- goto out;
- }
+ if (file_priv->event_space < e->length)
+ return -ENOMEM;
file_priv->event_space -= e->length;
@@ -721,8 +717,46 @@ int drm_event_reserve_init(struct drm_device *dev,
/* we *could* pass this in as arg, but everyone uses kfree: */
p->destroy = (void (*) (struct drm_pending_event *)) kfree;
-out:
+ return 0;
+}
+EXPORT_SYMBOL(drm_event_reserve_init_locked);
+
+/**
+ * drm_event_reserve_init - init a DRM event and reserve space for it
+ * @dev: DRM device
+ * @file_priv: DRM file private data
+ * @p: tracking structure for the pending event
+ * @e: actual event data to deliver to userspace
+ *
+ * This function prepares the passed in event for eventual delivery. If the event
+ * doesn't get delivered (because the IOCTL fails later on, before queuing up
+ * anything) then the even must be cancelled and freed using
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
+ *
+ * If callers embedded @p into a larger structure it must be allocated with
+ * kmalloc and @p must be the first member element.
+ *
+ * Callers which already hold dev->event_lock should use
+ * drm_event_reserve_init() instead.
+ *
+ * RETURNS:
+ *
+ * 0 on success or a negative error code on failure.
+ */
+int drm_event_reserve_init(struct drm_device *dev,
+ struct drm_file *file_priv,
+ struct drm_pending_event *p,
+ struct drm_event *e)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+ ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
spin_unlock_irqrestore(&dev->event_lock, flags);
+
return ret;
}
EXPORT_SYMBOL(drm_event_reserve_init);
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 4ec8bca643ac..aa602199cb5d 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1598,9 +1598,6 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
e->event.base.type = DRM_EVENT_VBLANK;
e->event.base.length = sizeof(e->event);
e->event.user_data = vblwait->request.signal;
- e->base.event = &e->event.base;
- e->base.file_priv = file_priv;
- e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
spin_lock_irqsave(&dev->event_lock, flags);
@@ -1616,12 +1613,11 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
goto err_unlock;
}
- if (file_priv->event_space < sizeof(e->event)) {
- ret = -EBUSY;
+ ret = drm_event_reserve_init_locked(dev, file_priv, &e->base, &e->event);
+
+ if (ret)
goto err_unlock;
- }
- file_priv->event_space -= sizeof(e->event);
seq = drm_vblank_count_and_time(dev, pipe, &now);
if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 306ef32ec086..1b71852d0a55 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -926,6 +926,10 @@ ssize_t drm_read(struct file *filp, char __user *buffer,
int drm_release(struct inode *inode, struct file *filp);
int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv);
unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait);
+int drm_event_reserve_init_locked(struct drm_device *dev,
+ struct drm_file *file_priv,
+ struct drm_pending_event *p,
+ struct drm_event *e);
int drm_event_reserve_init(struct drm_device *dev,
struct drm_file *file_priv,
struct drm_pending_event *p,
--
2.7.0.rc3
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