linux-kernel - Re: [PATCH] Bluetooth: btusb: Add debugfs to force toggling remote wakeup

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Message-ID: <CABBYNZLCjrJUiVzNf53XYM-ZHWL6TZD4yFNtNGOuYi=6s5Q+OA@mail.gmail.com>
Date: Wed, 24 Apr 2024 15:04:58 -0400
From: Luiz Augusto von Dentz <luiz.dentz@...il.com>
To: Archie Pusaka <apusaka@...gle.com>
Cc: linux-bluetooth <linux-bluetooth@...r.kernel.org>, 
	Johan Hedberg <johan.hedberg@...il.com>, Marcel Holtmann <marcel@...tmann.org>, 
	CrosBT Upstreaming <chromeos-bluetooth-upstreaming@...omium.org>, 
	Archie Pusaka <apusaka@...omium.org>, Abhishek Pandit-Subedi <abhishekpandit@...gle.com>, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Bluetooth: btusb: Add debugfs to force toggling remote wakeup

Hi Archie,

On Mon, Apr 22, 2024 at 3:25 AM Archie Pusaka <apusaka@...gle.com> wrote:
>
> From: Archie Pusaka <apusaka@...omium.org>
>
> Sometimes we want the controller to not wake the host up, e.g. to
> save the battery. Add some debugfs knobs to force the wake by BT
> behavior.
>
> Signed-off-by: Archie Pusaka <apusaka@...omium.org>
> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@...gle.com>
>
> ---
>
>  drivers/bluetooth/btusb.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 8bede0a335668..846b15fc3c04c 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -873,6 +873,9 @@ struct btusb_data {
>         unsigned cmd_timeout_cnt;
>
>         struct qca_dump_info qca_dump;
> +
> +       bool force_enable_remote_wake;
> +       bool force_disable_remote_wake;
>  };
>
>  static void btusb_reset(struct hci_dev *hdev)
> @@ -4596,6 +4599,10 @@ static int btusb_probe(struct usb_interface *intf,
>
>         debugfs_create_file("force_poll_sync", 0644, hdev->debugfs, data,
>                             &force_poll_sync_fops);
> +       debugfs_create_bool("force_enable_remote_wake", 0644, hdev->debugfs,
> +                           &data->force_enable_remote_wake);
> +       debugfs_create_bool("force_disable_remote_wake", 0644, hdev->debugfs,
> +                           &data->force_disable_remote_wake);
>
>         return 0;
>
> @@ -4702,6 +4709,18 @@ static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
>                 }
>         }
>
> +       if (!PMSG_IS_AUTO(message)) {
> +               if (data->force_enable_remote_wake) {
> +                       data->udev->do_remote_wakeup = 1;
> +                       if (test_bit(BTUSB_WAKEUP_AUTOSUSPEND, &data->flags))
> +                               data->udev->reset_resume = 0;
> +               } else if (data->force_disable_remote_wake) {
> +                       data->udev->do_remote_wakeup = 0;
> +                       if (test_bit(BTUSB_WAKEUP_AUTOSUSPEND, &data->flags))
> +                               data->udev->reset_resume = 1;
> +               }
> +       }
> +
>         return 0;
>  }
>
> --
> 2.44.0.769.g3c40516874-goog

There is a D-Bus interface available to overwrite the wakeup setting:

https://github.com/bluez/bluez/blob/master/doc/org.bluez.Device.rst#boolean-wakeallowed-readwrite

Or do you want a master switch for it? On the other hand aren't we
getting into the rfkill area if you really want to switch off radio
activity while suspended? That seems like a better idea then just
disable remote wakeup.

-- 
Luiz Augusto von Dentz