From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753623Ab3KQCNy (ORCPT ); Sat, 16 Nov 2013 21:13:54 -0500 Received: from plane.gmane.org ([80.91.229.3]:56189 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752409Ab3KQCNt (ORCPT ); Sat, 16 Nov 2013 21:13:49 -0500 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Nikolaus Meine Subject: Re: =?utf-8?b?eGhjaV9oY2Q=?= 3.12 regression Date: Sun, 17 Nov 2013 02:13:22 +0000 (UTC) Message-ID: References: <20131110175002.GA26281@invalid> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: sea.gmane.org User-Agent: Loom/3.14 (http://gmane.org/) X-Loom-IP: 82.83.204.222 (Mozilla/5.0 (X11; Linux x86_64; rv:20.0) Gecko/20100101 Firefox/20.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nikolaus Meine tnt.uni-hannover.de> writes: > > After upgrading from kernel 3.11 to 3.12 my USB 3.0 card reader > (Transcend RDF8) stopped working with the same error. > > I managed to find the code line which triggered the erroneous behaviour: > > It's the definition of the macro xhci_dbg(...) in xhci.h line 1590/1591. > > In 3.11 it is > do { if (XHCI_DEBUG) dev_dbg(...); } while (0) > > XHCI_DEBUG is defined as 0 because XHCI_HCD_DEBUGGING is not defined > so this macro collapses to nothing. > > In 3.12 xhci_dbg(...) is defined as > dev_dbg(...) > which actually calls dev_printk(...) because DEBUG is defined. > > If I define xhci_dbg() in 3.12 as > do { } while (0) > my card reader starts working again. > > That was the good news. > The bad news is that I have no idea why calling dev_printk(...) > does any harm here. Maybe it's a timing problem. > > Best Regards > Nikolaus Meine > Hello once again! I have to correct me previous post: The card reader does actually work with 3.12 so it's just the dumping of debug messages which was enabled in 3.12, no timing problem. Best Regards Nikolaus Meine