Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) Subject: Re: [PATCHv2] Bluetooth: btusb: Fix Intel controller hang after shutdown From: Marcel Holtmann In-Reply-To: <1432218957-3400-1-git-send-email-loic.poulain@intel.com> Date: Thu, 21 May 2015 21:56:19 +0200 Cc: tedd.an@intel.com, linux-bluetooth@vger.kernel.org Message-Id: <69A96222-5518-4341-9F0B-32F3CEACCC35@holtmann.org> References: <1432218957-3400-1-git-send-email-loic.poulain@intel.com> To: Loic Poulain Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Tedd, > The vendor command (0xfc3f) in btusb_shutdown_intel causes an internal > reset with old firmware. After that, upcoming HCI command will hang due > to a controller bug with the first HCI command sent to it. > The workaround is to send HCI Reset command first which will reset the > number of completed commands. > > Signed-off-by: Loic Poulain > --- > v2: Send HCI reset from shutdown instead of using HCI_QUIRK_RESET_ON_CLOSE > drivers/bluetooth/btusb.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c > index d21f3b4..589f30c 100644 > --- a/drivers/bluetooth/btusb.c > +++ b/drivers/bluetooth/btusb.c > @@ -2705,6 +2705,19 @@ static int btusb_shutdown_intel(struct hci_dev *hdev) > } > kfree_skb(skb); > > + /* The 0xfc3f command causes an internal reset with old firmware. > + * In order to avoid the Bug with the first HCI command, we have > + * to send a HCI reset which will reset the number of completed > + * command. > + */ > + skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL, HCI_INIT_TIMEOUT); > + if (IS_ERR(skb)) { > + BT_ERR("%s: Shutdown HCI reset command failed (%ld)", > + hdev->name, PTR_ERR(skb)); > + return PTR_ERR(skb); > + } > + kfree_skb(skb); > + please test this change and see if it still has the desired effect. ACK or NACK the patch based on your testing. Regards Marcel