Received-SPF: pass (google.com: best guess record for domain of linux-bluetooth-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain;
        charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\))
Subject: Re: [PATCH 1/1] bluetooth: update default BLE connection params
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <705dbccb-58a9-7adc-8430-c16b395c27e5@gmail.com>
Date:   Thu, 5 Sep 2019 17:34:03 +0200
Cc:     Johan Hedberg <johan.hedberg@gmail.com>,
        Andreas Kemnade <andreas@kemnade.info>,
        Jamie Mccrae <Jamie.Mccrae@lairdconnect.com>,
        "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
Content-Transfer-Encoding: 8BIT
Message-Id: <4BFC2A23-1D8A-4021-BB74-418A13676E65@holtmann.org>
References: <705dbccb-58a9-7adc-8430-c16b395c27e5@gmail.com>
To:     Carey Sonsino <csonsino@gmail.com>
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hi Carey,

> Update the default BLE connection parameters.
> 
> Commit c49a8682fc5d298d44e8d911f4fa14690ea9485e introduced a bounds
> check on connection interval update requests, but the default min/max
> values were left at 24-40 (30-50ms) which caused problems for devices
> that want to negotiate connection intervals outside of those bounds.
> 
> Setting the default min/max connection interval to the full allowable
> range in the bluetooth specification restores the default Linux behavior
> of allowing remote devices to negotiate their desired connection
> interval, while still permitting the system administrator to later
> narrow the range.
> 
> The default supervision timeout must also be modified to accommodate
> the max connection interval increase.  The new default value meets the
> requirements of the bluetooth specification and the conditions in
> the hci_check_conn_params function.
> 
> The downside to modifying the default supervision timeout is that
> it will take longer (about 10 seconds) to detect a link loss condition.
> 
> Fixes c49a8682fc5d: (validate BLE connection interval updates)

I decided to revert c49a8682fc5d and we need an overall better solution for handling connection parameters.

Regards

Marcel