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Date:   Mon, 25 Jul 2022 15:34:21 -0700
Message-Id: <20220725153415.v2.1.Ia18502557c4ba9ba7cd2d1da2bae3aeb71b37e4e@changeid>
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Subject: [PATCH v2] Bluetooth: Always set event mask on suspend
From:   Abhishek Pandit-Subedi <abhishekpandit@google.com>
To:     luiz.dentz@gmail.com, linux-bluetooth@vger.kernel.org
Cc:     Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
        stable@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
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Precedence: bulk

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

When suspending, always set the event mask once disconnects are
successful. Otherwise, if wakeup is disallowed, the event mask is not
set before suspend continues and can result in an early wakeup.

Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier")
Cc: stable@vger.kernel.org
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
Observed on ChromeOS as follows:

< HCI Command: Disconnect (0x01|0x0006) plen 3
        Handle: 256
        Reason: Remote Device Terminated due to Power Off (0x15)
> HCI Event: Command Status (0x0f) plen 4
      Disconnect (0x01|0x0006) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Device Disconnected (0x000c) plen 8
        BR/EDR Address: 04:52:C7:C3:65:B5 (Bose Corporation)
        Reason: Connection terminated by local host for suspend (0x05)
@ MGMT Event: Controller Suspended (0x002d) plen 1
        Suspend state: Disconnected and not scanning (1)
> HCI Event: Disconnect Complete (0x05) plen 4
        Status: Success (0x00)
        Handle: 256
        Reason: Connection Terminated By Local Host (0x16)

The expectation is that we should see Set Event Mask before completing
the suspend so that the `Disconnect Complete` doesn't wake us up.


Changes in v2:
- Added fixes tag and cc stable

 net/bluetooth/hci_sync.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 148ce629a59f..e6d804b82b67 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -5297,6 +5297,9 @@ int hci_suspend_sync(struct hci_dev *hdev)
 		return err;
 	}
 
+	/* Update event mask so only the allowed event can wakeup the host */
+	hci_set_event_mask_sync(hdev);
+
 	/* Only configure accept list if disconnect succeeded and wake
 	 * isn't being prevented.
 	 */
@@ -5308,9 +5311,6 @@ int hci_suspend_sync(struct hci_dev *hdev)
 	/* Unpause to take care of updating scanning params */
 	hdev->scanning_paused = false;
 
-	/* Update event mask so only the allowed event can wakeup the host */
-	hci_set_event_mask_sync(hdev);
-
 	/* Enable event filter for paired devices */
 	hci_update_event_filter_sync(hdev);
 
-- 
2.37.1.359.gd136c6c3e2-goog