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In-Reply-To: <87y29o58su.fsf@baylibre.com>
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
Date:   Tue, 3 Aug 2021 14:42:07 +0800
Message-ID: <CAAd53p4Ss1Z-7CB4g=_xZYxo1xDz6ih6GHUuMcgncy+yNAfU4w@mail.gmail.com>
Subject: Re: [PATCH v2] Bluetooth: Shutdown controller after workqueues are
 flushed or cancelled
To:     Mattijs Korpershoek <mkorpershoek@baylibre.com>
Cc:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Fabien Parent <fparent@baylibre.com>,
        Sean Wang <sean.wang@mediatek.com>,
        "open list:BLUETOOTH SUBSYSTEM" <linux-bluetooth@vger.kernel.org>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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Hi Mattijs,

On Fri, Jul 30, 2021 at 7:40 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> Hi Kai-Heng,

[snipped]

> Thank you for your help. Sorry I did not post the logs previously.
>
> dmesg: https://pastebin.com/tpWDNyQr
> ftrace on btmtksdio: https://pastebin.com/jmhvmwUw

Seems like btmtksdio needs shudown() to be called before flush().
Since the order was there for a very long time, changing the calling
order indeed can break what driver expects.
Can you please test the following patch:
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2560ed2f144d..a61e610a400c 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1785,6 +1785,14 @@ int hci_dev_do_close(struct hci_dev *hdev)
        aosp_do_close(hdev);
        msft_do_close(hdev);

+       if (!hci_dev_test_flag(hdev, HCI_UNREGISTER) &&
+           !hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
+           test_bit(HCI_UP, &hdev->flags)) {
+               /* Execute vendor specific shutdown routine */
+               if (hdev->shutdown)
+                       hdev->shutdown(hdev);
+       }
+
        if (hdev->flush)
                hdev->flush(hdev);

@@ -1798,14 +1806,6 @@ int hci_dev_do_close(struct hci_dev *hdev)
                clear_bit(HCI_INIT, &hdev->flags);
        }

-       if (!hci_dev_test_flag(hdev, HCI_UNREGISTER) &&
-           !hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
-           test_bit(HCI_UP, &hdev->flags)) {
-               /* Execute vendor specific shutdown routine */
-               if (hdev->shutdown)
-                       hdev->shutdown(hdev);
-       }
-
        /* flush cmd  work */
        flush_work(&hdev->cmd_work);

Kai-Heng

>
> Mattijs
> >
> > Kai-Heng
> >
> >>
> >> Thanks,
> >> Mattijs Korpershoek
> >>
> >>
> >> >
> >> > Regards
> >> >
> >> > Marcel