[PATCH v5 02/12] media: uvcvideo: Allow more that one asyc_ctrl

[Ricardo Ribalda]

The current implementation allocates memory for only one async_control.
If we get a second event before we have processed the previous one, the
old one gets lost.

Introduce a dynamic memory allocation and a list to handle the
async_controls.

Signed-off-by: Ricardo Ribalda <riba...@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 49 ++++++++++++++++++++++++++------
 drivers/media/usb/uvc/uvcvideo.h | 19 ++++++++-----
 2 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index aa18dcdf8165..69b2fc6ce12c 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1275,11 +1275,9 @@ static void uvc_ctrl_send_slave_event(struct 
uvc_video_chain *chain,
        uvc_ctrl_send_event(chain, handle, ctrl, mapping, val, changes);
 }
 
-static void uvc_ctrl_status_event_work(struct work_struct *work)
+static void __uvc_ctrl_status_event_work(struct uvc_device *dev,
+                                        struct uvc_ctrl_work *w)
 {
-       struct uvc_device *dev = container_of(work, struct uvc_device,
-                                             async_ctrl.work);
-       struct uvc_ctrl_work *w = &dev->async_ctrl;
        struct uvc_video_chain *chain = w->chain;
        struct uvc_control_mapping *mapping;
        struct uvc_control *ctrl = w->ctrl;
@@ -1321,23 +1319,54 @@ static void uvc_ctrl_status_event_work(struct 
work_struct *work)
                           ret);
 }
 
+static void uvc_ctrl_status_event_work(struct work_struct *work)
+{
+       struct uvc_device *dev = container_of(work, struct uvc_device,
+                                             async_ctrl_work);
+       struct uvc_ctrl_work *w;
+
+       do {
+               mutex_lock(&dev->async_ctrl_lock);
+               w = list_first_entry_or_null(&dev->async_ctrl_list,
+                                            struct uvc_ctrl_work,
+                                            list);
+               if (w)
+                       list_del(&w->list);
+               mutex_unlock(&dev->async_ctrl_lock);
+
+               if (!w)
+                       return;
+
+               __uvc_ctrl_status_event_work(dev, w);
+               kfree(w);
+       } while (w);
+}
+
 bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
                           struct uvc_control *ctrl, const u8 *data)
 {
        struct uvc_device *dev = chain->dev;
-       struct uvc_ctrl_work *w = &dev->async_ctrl;
+       struct uvc_ctrl_work *w;
 
        if (list_empty(&ctrl->info.mappings)) {
                ctrl->handle = NULL;
                return false;
        }
 
+       w = kzalloc(sizeof(*w), GFP_KERNEL);
+       if (WARN(!w, "Not enough memory to trigger uvc event"))
+               return false;
+
        memcpy(w->data, data, ctrl->info.size);
        w->urb = urb;
        w->chain = chain;
        w->ctrl = ctrl;
 
-       schedule_work(&w->work);
+       mutex_lock(&dev->async_ctrl_lock);
+       list_add_tail(&w->list, &dev->async_ctrl_list);
+       mutex_unlock(&dev->async_ctrl_lock);
+
+       schedule_work(&dev->async_ctrl_work);
 
        return true;
 }
@@ -2277,7 +2306,9 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
        struct uvc_entity *entity;
        unsigned int i;
 
-       INIT_WORK(&dev->async_ctrl.work, uvc_ctrl_status_event_work);
+       INIT_WORK(&dev->async_ctrl_work, uvc_ctrl_status_event_work);
+       mutex_init(&dev->async_ctrl_lock);
+       INIT_LIST_HEAD(&dev->async_ctrl_list);
 
        /* Walk the entities list and instantiate controls */
        list_for_each_entry(entity, &dev->entities, list) {
@@ -2348,8 +2379,8 @@ void uvc_ctrl_cleanup_device(struct uvc_device *dev)
        unsigned int i;
 
        /* Can be uninitialized if we are aborting on probe error. */
-       if (dev->async_ctrl.work.func)
-               cancel_work_sync(&dev->async_ctrl.work);
+       if (dev->async_ctrl_work.func)
+               cancel_work_sync(&dev->async_ctrl_work);
 
        /* Free controls and control mappings for all entities. */
        list_for_each_entry(entity, &dev->entities, list) {
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 0db6c2e0bd98..afcaf49fad1a 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -637,6 +637,14 @@ struct uvc_device_info {
        u32     meta_format;
 };
 
+struct uvc_ctrl_work {
+       struct list_head list;
+       struct urb *urb;
+       struct uvc_video_chain *chain;
+       struct uvc_control *ctrl;
+       u8 data[UVC_MAX_STATUS_SIZE];
+};
+
 struct uvc_device {
        struct usb_device *udev;
        struct usb_interface *intf;
@@ -673,13 +681,10 @@ struct uvc_device {
        struct input_dev *input;
        char input_phys[64];
 
-       struct uvc_ctrl_work {
-               struct work_struct work;
-               struct urb *urb;
-               struct uvc_video_chain *chain;
-               struct uvc_control *ctrl;
-               u8 data[UVC_MAX_STATUS_SIZE];
-       } async_ctrl;
+       /* Async control */
+       struct work_struct async_ctrl_work;
+       struct list_head async_ctrl_list;
+       struct mutex async_ctrl_lock;
 };
 
 enum uvc_handle_state {
-- 
2.29.2.684.gfbc64c5ab5-goog