Return-Path: Message-ID: <52EA4EF5.5000007@ahsoftware.de> Date: Thu, 30 Jan 2014 14:09:09 +0100 From: Alexander Holler MIME-Version: 1.0 To: Gianluca Anzolin , Marcel Holtmann CC: "Gustavo F. Padovan" , peter@hurleysoftware.com, "linux-bluetooth@vger.kernel.org development" , Greg KH , jslaby@suse.cz, stable@vger.kernel.org Subject: Re: [PATCH v3 0/4] Regression fixes for rfcomm/tty.c References: <1389039834-24491-1-git-send-email-gianluca@sottospazio.it> <53C8DDF7-94EA-4E01-A2A9-C366F9F85530@holtmann.org> <52DCDF84.1040902@ahsoftware.de> <20140128083154.GA29060@sottospazio.it> In-Reply-To: <20140128083154.GA29060@sottospazio.it> Content-Type: text/plain; charset=us-ascii; format=flowed List-ID: Am 28.01.2014 09:31, schrieb Gianluca Anzolin: > Unfortunately it seems I overlooked the fact that rfcomm_dev_activate() is > called with the port->mutex held. So patches 2/3/4 cause a regression I missed > because I didn't turn on the appropriate debug options (circular locking > dependency, a bug report already appeared on this list). > > I'm afraid this all stems from my partial knowledge of the tty_port code and > unfortunately I don't know how to solve the problem right now. Understandable, it's like a mine field. ;) Maybe it might make sense to add Alan Cox to Cc, I think he's active again and knows a lot about tty_port. > I think it's better to revert those patches for the moment. I prefer to still use those patches because without them, I have a more serious problem (at least for my use cases, which happily haven't run into that deadlock). But thanks for notifying me/us about the possibility of a deadlock when using your patches. Regards, Alexander Holler