[media] v4l: vb2: Add a function to discard all DONE buffers
When suspending a device while a video stream is active all buffers
marked as done but not dequeued yet will be kept across suspend and
given back to userspace after resume. This will result in outdated
buffers being dequeued.
Introduce a new vb2 function to mark all done buffers as erroneous
instead, to be used by drivers at resume time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 349e659..7c4489c 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1200,6 +1200,30 @@
EXPORT_SYMBOL_GPL(vb2_buffer_done);
/**
+ * vb2_discard_done() - discard all buffers marked as DONE
+ * @q: videobuf2 queue
+ *
+ * This function is intended to be used with suspend/resume operations. It
+ * discards all 'done' buffers as they would be too old to be requested after
+ * resume.
+ *
+ * Drivers must stop the hardware and synchronize with interrupt handlers and/or
+ * delayed works before calling this function to make sure no buffer will be
+ * touched by the driver and/or hardware.
+ */
+void vb2_discard_done(struct vb2_queue *q)
+{
+ struct vb2_buffer *vb;
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->done_lock, flags);
+ list_for_each_entry(vb, &q->done_list, done_entry)
+ vb->state = VB2_BUF_STATE_ERROR;
+ spin_unlock_irqrestore(&q->done_lock, flags);
+}
+EXPORT_SYMBOL_GPL(vb2_discard_done);
+
+/**
* __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
* v4l2_buffer by the userspace. The caller has already verified that struct
* v4l2_buffer has a valid number of planes.