Return-Path: Subject: Re: max 16 hci devices on usb 2.0 From: Marcel Holtmann To: Bram Jansen Cc: linux-bluetooth@vger.kernel.org In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Date: Sat, 16 Jan 2010 17:44:23 -0800 Message-ID: <1263692663.5591.54.camel@localhost.localdomain> Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Bram, > I have a question regarding the connection of 16 hci devices to a linux box. > I've been looking around for quite some time and I was not able to find > something useful, therefore I hope anyone of you guys is able to point me in > the right direction. > > We have used quite a few kernel versions to try to connect 16 hci devices to > one system with usb 2.0 enabled. > This gives a problem after 7 devices. Devices hci7-hci15 give timeouts and > errors after initializing. > > We solved this problem by disabling ehci in the kernel, so the bluetooth had > to use usb 1.1 (ohci) > with these settings it works without any problems and all 16 hci devices are > initialized properly after insertion/boot > > now there has come the need for usb 2.0 on the same system. > > Is there a known solution for this issue? you better ask such questions on the Linux USB mailing list since I have no idea why sometimes the hubs causes problems. As a side note. The 16 HCI devices limit is not fixed actually. You can just compile your own libbluetooth with a different limit. The kernel supports as many devices as you have memory :) Regards Marcel