From: Jassi Brar <jassisinghbrar@xxxxxxxxx> Hi, > The mailbox API has a `peek_data` operation. Its intent and > documentation is rather ambiguous; at first glance and based on the > name, it seems like it should only check for whether data is currently > pending in the controller, without actually delivering it to the > consumer. However, this interpretation is not useful for anything: the > function can be called from atomic context, but without a way to > actually *poll* for data from atomic context, there is no use in just > checking for whether data is available. > Not exactly... the 'peek_data' is a means for client driver to hint the controller driver that some data might have arrived (for controllers that don't have anything like RX-Irq). The controller is then expected to dispatch data after "not necessarily atomic" read. For example, a quick look at some bit may tell there is data available, but actually reading the data from buffer may be non-atomic. In your case, you could already implement the patch-7/7 by simply calling it peek_data() instead of poll_data(). Its ok to call mbox_chan_received_data() from peek_data() because your data-read can be atomic. Also some platforms may not have users of peek_data upstream (yet), so simply weeding them out may not be right. thanks.
