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Subject: Re: [PATCH BlueZ] policy: Change AutoEnable default to true
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <20220413222425.187199-1-luiz.dentz@gmail.com>
Date:   Tue, 19 Apr 2022 10:48:43 +0200
Cc:     linux-bluetooth@vger.kernel.org
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Message-Id: <61417C2F-0009-4123-8F1C-DACC4A46073D@holtmann.org>
References: <20220413222425.187199-1-luiz.dentz@gmail.com>
To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Precedence: bulk

Hi Luiz,

> This changes the default of AutoEnable to true so controllers are power
> up by default.
> 
> Fixes: https://github.com/bluez/bluez/issues/328
> ---
> plugins/policy.c | 6 +++++-
> src/main.conf    | 4 ++--
> 2 files changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/plugins/policy.c b/plugins/policy.c
> index 48f5db7d3..0bbdbfc88 100644
> --- a/plugins/policy.c
> +++ b/plugins/policy.c
> @@ -892,7 +892,11 @@ static int policy_init(void)
> 	}
> 
> 	auto_enable = g_key_file_get_boolean(conf, "Policy", "AutoEnable",
> -									NULL);
> +								&gerr);
> +	if (gerr) {
> +		g_clear_error(&gerr);
> +		auto_enable = true;
> +	}
> 
> 	resume_delay = g_key_file_get_integer(
> 			conf, "Policy", "ResumeDelay", &gerr);
> diff --git a/src/main.conf b/src/main.conf
> index 401796235..91b98b8c4 100644
> --- a/src/main.conf
> +++ b/src/main.conf
> @@ -276,8 +276,8 @@
> 
> # AutoEnable defines option to enable all controllers when they are found.
> # This includes adapters present on start as well as adapters that are plugged
> -# in later on. Defaults to 'false'.
> -#AutoEnable=false
> +# in later on. Defaults to 'true'.
> +#AutoEnable=true

so this is problematic since all wireless technology daemon where design to not automatically activate their hardware. It needed a system above like ConnMan, NetworkManager or even the UI to start the operation.

It is especially tricky since bluetoothd doesn’t remember the last state. So if you power off, then restart, it is on again the next time around. Not something you might have wanted. Using false here is the right choice as a default.

If you install systemd-rfkill and want to auto-power once soft-rfkill is released and systemd-rfkill remembers the state persistently, then you need to install your main.conf with AutoEnable=true. That is a distro choice.

Regards

Marcel