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

Ricardo Ribalda
2020-12-21T18:36:16Z

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 <ribalda@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