Return-Path: MIME-Version: 1.0 In-Reply-To: <20140423113722.GA2967@t440s.lan> References: <1397588651-13459-1-git-send-email-lukasz.rymanowski@tieto.com> <20140423113722.GA2967@t440s.lan> Date: Wed, 23 Apr 2014 13:55:31 +0200 Message-ID: Subject: Re: [PATCH] Bluetooth: Allow discovery during advertising From: Lukasz Rymanowski To: Lukasz Rymanowski , "linux-bluetooth@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Johan On 23 April 2014 13:37, Johan Hedberg wrote: > Hi Lukasz, > > On Tue, Apr 15, 2014, Lukasz Rymanowski wrote: >> With this patch it is possible to start scan when device does >> advertising. >> >> Most of chips do support such state combination, so there is no reason >> for blocking it here. >> If chip does not support this, kernel should get command status event >> with command disallowed status which should not make any problems. >> >> Signed-off-by: Lukasz Rymanowski >> --- >> net/bluetooth/mgmt.c | 7 ------- >> 1 file changed, 7 deletions(-) >> >> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c >> index 54abbce..57cef73 100644 >> --- a/net/bluetooth/mgmt.c >> +++ b/net/bluetooth/mgmt.c >> @@ -3474,13 +3474,6 @@ static int start_discovery(struct sock *sk, struct hci_dev *hdev, >> goto failed; >> } >> >> - if (test_bit(HCI_ADVERTISING, &hdev->dev_flags)) { >> - err = cmd_status(sk, hdev->id, MGMT_OP_START_DISCOVERY, >> - MGMT_STATUS_REJECTED); >> - mgmt_pending_remove(cmd); >> - goto failed; >> - } >> - >> /* If controller is scanning, it means the background scanning >> * is running. Thus, we should temporarily stop it in order to >> * set the discovery scanning parameters. > > The general principle we've been following is that we don't send HCI > commands to the controller that we know will fail. In this case we do > track the supported states in hdev->le_states so you should be using > that to determine whether the command should fail or not. > Yes that was my first idea, but number of possible states combination is just "amazing", plus I checked all dual mode controllers I had around me and all of them do support that state combinations which we need here. Have you seen controllers doing different? I so, why they do it :) ? > You might need to add tracking of the advertising type though (similar > to how we track the own_addr_type for advertising) to know which state > combination to check. > > Johan \Łukasz