Re: [PATCH] Bluetooth: Clear suspend tasks on unregister

From: Marcel Holtmann
Date: Mon Aug 31 2020 - 11:50:03 EST


Hi Abhishek,

> While unregistering, make sure to clear the suspend tasks before
> cancelling the work. If the unregister is called during resume from
> suspend, this will unnecessarily add 2s to the resume time otherwise.
>
> Fixes: 4e8c36c3b0d73d (Bluetooth: Fix suspend notifier race)
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
> ---
> This was discovered with RT8822CE using the btusb driver. This chipset
> will reset on resume during system suspend and was unnecessarily adding
> 2s to every resume. Since we're unregistering anyway, there's no harm in
> just clearing the pending events.
>
> net/bluetooth/hci_core.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 68bfe57b66250f..ed4cb3479433c0 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -3442,6 +3442,16 @@ void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr,
> }
> }
>
> +static void hci_suspend_clear_tasks(struct hci_dev *hdev)
> +{
> + int i;
> +
> + for (i = 0; i < __SUSPEND_NUM_TASKS; ++i)
> + clear_bit(i, hdev->suspend_tasks);

I prefer i++ instead of ++i.

Regards

Marcel