Hi Daniel,
Thank you for the patch.
On Saturday 09 January 2016 14:28:46 Daniel Vetter wrote:
> There's really no reason to not do so, instead of replicating this
> for every use-case and every driver. Now we can't just nuke the events,
> since that would still mean that all drm_event users would need to know
> when that has happened, since calling e.g. drm_send_event isn't allowed
> any more. Instead just unlink them from the file, and detect this case
> and handle it appropriately in all functions.
>
> v2: Adjust existing kerneldoc too.
>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
> drivers/gpu/drm/drm_fops.c | 35 ++++++++++++++++++++++++++---------
> include/drm/drmP.h | 2 ++
> 2 files changed, 28 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index d85af1b2a238..d32b24c74e08 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -264,6 +264,7 @@ static int drm_open_helper(struct file *filp, struct
> drm_minor *minor) INIT_LIST_HEAD(&priv->fbs);
> mutex_init(&priv->fbs_lock);
> INIT_LIST_HEAD(&priv->blobs);
> + INIT_LIST_HEAD(&priv->pending_event_list);
> INIT_LIST_HEAD(&priv->event_list);
> init_waitqueue_head(&priv->event_wait);
> priv->event_space = 4096; /* set aside 4k for event buffer */
> @@ -353,18 +354,16 @@ static void drm_events_release(struct drm_file
> *file_priv) {
> struct drm_device *dev = file_priv->minor->dev;
> struct drm_pending_event *e, *et;
> - struct drm_pending_vblank_event *v, *vt;
> unsigned long flags;
>
> spin_lock_irqsave(&dev->event_lock, flags);
>
> - /* Remove pending flips */
> - list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
> - if (v->base.file_priv == file_priv) {
> - list_del(&v->base.link);
> - drm_vblank_put(dev, v->pipe);
> - v->base.destroy(&v->base);
> - }
Where does this code go ?
> + /* Unlink pending events */
> + list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
> + pending_link) {
> + list_del(&e->pending_link);
> + e->file_priv = NULL;
> + }
>
> /* Remove unconsumed events */
> list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
> @@ -712,6 +711,7 @@ int drm_event_reserve_init(struct drm_device *dev,
> file_priv->event_space -= e->length;
>
> p->event = e;
> + list_add(&p->pending_link, &file_priv->pending_event_list);
> p->file_priv = file_priv;
>
> /* we *could* pass this in as arg, but everyone uses kfree: */
> @@ -736,7 +736,10 @@ void drm_event_cancel_free(struct drm_device *dev,
> {
> unsigned long flags;
> spin_lock_irqsave(&dev->event_lock, flags);
> - p->file_priv->event_space += p->event->length;
> + if (p->file_priv) {
> + p->file_priv->event_space += p->event->length;
> + list_del(&p->pending_link);
> + }
> spin_unlock_irqrestore(&dev->event_lock, flags);
> p->destroy(p);
> }
> @@ -750,11 +753,21 @@ EXPORT_SYMBOL(drm_event_cancel_free);
> * This function sends the event @e, initialized with
> drm_event_reserve_init(),
> * to its associated userspace DRM file. Callers must already hold
> * dev->event_lock, see drm_send_event() for the unlocked version.
> + *
> + * Note that the core will take care of unlinking and disarming events when
> the
> + * corresponding DRM file is closed. Drivers need to worry about that and
s/need to/need not/ ?
> can
> + * call this function upon completion of the asynchrnous work
s/asynchrnous/asynchronous/
> unconditionally. */
> void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event
> *e) {
> assert_spin_locked(&dev->event_lock);
>
> + if (!e->file_priv) {
I don't think this could happen before this patch as e->file_priv is
dereferenced below, and I don't see anything in this patch that makes the
condition possible.
> + e->destroy(e);
> + return;
> + }
> +
> + list_del(&e->pending_link);
> list_add_tail(&e->link,
> &e->file_priv->event_list);
> wake_up_interruptible(&e->file_priv->event_wait);
> @@ -769,6 +782,10 @@ EXPORT_SYMBOL(drm_send_event_locked);
> * This function sends the event @e, initialized with
> drm_event_reserve_init(),
> * to its associated userspace DRM file. This function acquires
> dev->event_lock,
> * see drm_send_event_locked() for callers which already hold this lock.
> + *
> + * Note that the core will take care of unlinking and disarming events when
> the
> + * corresponding DRM file is closed. Drivers need to worry about that and
s/need to/need not/ ?
> can
> + * call this function upon completion of the asynchrnous work
s/asynchrnous/asynchronous/
> unconditionally. */
> void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
> {
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index ae73abf5c2cf..3d78a7406d54 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -283,6 +283,7 @@ struct drm_ioctl_desc {
> struct drm_pending_event {
> struct drm_event *event;
> struct list_head link;
> + struct list_head pending_link;
> struct drm_file *file_priv;
> pid_t pid; /* pid of requester, no guarantee it's valid by the time
> we deliver the event, for tracing only */
> @@ -346,6 +347,7 @@ struct drm_file {
> struct list_head blobs;
>
> wait_queue_head_t event_wait;
> + struct list_head pending_event_list;
> struct list_head event_list;
> int event_space;
--
Regards,
Laurent Pinchart
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