Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) Subject: Re: bt dongle goes awry after too many connections From: Marcel Holtmann In-Reply-To: Date: Mon, 2 Mar 2015 16:17:54 -0800 Cc: linux-bluetooth@vger.kernel.org Message-Id: <6EDCDCB4-6F4D-4DE6-88DB-88D333FC2CCC@holtmann.org> References: To: Tim Tisdall Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Tim, > I have a "0a5c:21e8 Broadcom Corp.BCM20702A0 Bluetooth 4.0" usb > bluetooth dongle I'm using to connect to multiple BLE devices. It > used to be that I could connect to 7 devices with no issues and then > when I tried to connect to the 8th device I'd get a > CONNECTION_LIMIT_EXCEEDED error. In my code I would then tag that > dongle as having a connection limit of 7 and limit the number of > connections. > > Recently I was using this code and found that it no longer works. The > dongle seems to "successfully" connect to ~13 devices but things don't > work properly. At least half of the devices no longer respond to GATT > commands sent to it. I issue a GATT command after connecting to each > device to read some attributes and most simply do nothing (no error, > no response, nothing). > > Any way, I'm not really familiar with how things are laid out in the > kernel so I'm not really sure where that CONNECTION_LIMIT_EXCEEDED was > being created before and why it's no longer working as expected. I > tried looking through the git logs in "btusb" and "bluetooth" modules > and didn't really see anything pertinent. have to tried to install the firmware for the Broadcom dongle. It could be well that the firmware update fixes a few of these bugs with the LE connection behavior. You can grab the firmware file from the Windows driver and use the hex2hcd utility to convert it into a format that the btusb.ko kernel driver understands. Regards Marcel