Hi Tedd, >>> This patch cancels the hci_request timeout work if the expected event >>> is recevied. >> >> The timer you're canceling isn't hci_request specific, so I'm not sure >> why you're making that reference here? You might want to provide some >> more detailed explanation in the commit message. > > When the command is sent with __hci_cmd_sync_ev() and expected event is > other than Command_Complete or > Command_Status, especially, vendor specific event (0xFF), the function > returns the skb filled with > event parameters properly, but there is tx timeout error because the > cmd_timer is not canceled. the cmd_timer is protecting the cmd_q and with that is doing exactly the right thing here. It is here for handling cmd_status and cmd_complete events and with that updating ncmd and HCI command flow control. So we can not just cancel the timer here. It seems that __hci_cmd_sync_ev is actually not used at all at the moment. However it works just fine when you get the interim cmd_status as done by all HCI commands. The problem is that you are not seeing the cmd_status and thus you have problems here. But we can not just ignore the missing cmd_status. If we do, then ncmd is out of date and HCI flow control is broken at that point. With that said, we can neither use __hci_cmd_sync nor __hci_cmd_sync_ev for Bluetooth controllers that do not obey the HCI command flow control. So sending commands via cmd_q is not an option here. The only way I am thinking of being able to work around such behavior is by introducing separate functionality to handle it. So we might need __hci_cmd_raw_sync and __hci_cmd_raw_sync_ev that allows scheduling on raw_q and skipping cmd_complete and cmd_status processing. This however would mean that __hci_cmd_raw_sync can never return data from cmd_complete events (meaning it is actually not _sync in the sense of returning data, even while the name would suggest it). Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
