Hi Jonas, On Tue, Jan 2, 2024 at 1:59 PM Jonas Dreßler <verdre@xxxxxxx> wrote: > > Since commit 4c67bc74f016b0d360b8573e18969c0ff7926974, we retry connecting > later when we get a "Command Disallowed" error returned by "Create > Connection". > > In this commit the intention was to retry only once, and give up if we see > "Command Disallowed" again on the second try. > > This made sense back then when the retry was initiated *only* from the > "Connect Complete" event. If we received that event, we knew that now the > card now must have a "free slot" for a new connection request again. These > days we call hci_conn_check_pending() from a few more places though, and > in these places we can't really be sure that there's a "free slot" on the > card, so the second try to "Create Connection" might fail again. > > Deal with this by being less strict about these retries and try again > every time we get "Command Disallowed" errors, removing the limitation to > only two attempts. > > Since this can potentially cause us to enter an endless cycle of > reconnection attempts, we'll add some guarding against that with the next > commit. Don't see where you are doing such guarding, besides you seem to assume HCI_ERROR_COMMAND_DISALLOWED would always means the controller is busy, or something like that, but it could perform the connection later, but that may not always be the case, thus why I think reconnecting just a few number of times is better, if you really need to keep retrying then this needs to be controlled by a policy in userspace not hardcoded in the kernel, well I can even argument that perhaps the initial number of reconnection shall be configurable so one don't have to recompile the kernel if that needs changing. > Signed-off-by: Jonas Dreßler <verdre@xxxxxxx> > --- > net/bluetooth/hci_event.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index e8b4a0126..e1f5b6f90 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -2323,12 +2323,13 @@ static void hci_cs_create_conn(struct hci_dev *hdev, __u8 status) > > if (status) { > if (conn && conn->state == BT_CONNECT) { > - if (status != HCI_ERROR_COMMAND_DISALLOWED || conn->attempt > 2) { > + if (status == HCI_ERROR_COMMAND_DISALLOWED) { > + conn->state = BT_CONNECT2; > + } else { > conn->state = BT_CLOSED; > hci_connect_cfm(conn, status); > hci_conn_del(conn); > - } else > - conn->state = BT_CONNECT2; > + } > } > } else { > if (!conn) { > -- > 2.43.0 > -- Luiz Augusto von Dentz