From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 1/1] mmc: sdhci: fix lockdep error on tunning routine Date: Wed, 15 Jan 2014 11:09:04 +0100 Message-ID: <20140115100904.GX31570@twins.programming.kicks-ass.net> References: <1387797184-18958-1-git-send-email-b29396@freescale.com> <20140113120435.GQ31570@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from merlin.infradead.org ([205.233.59.134]:60554 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751253AbaAOKJZ (ORCPT ); Wed, 15 Jan 2014 05:09:25 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Dong Aisheng Cc: Dong Aisheng , "linux-mmc@vger.kernel.org" , Shawn Guo , Sascha Hauer , Chris Ball , "linux-arm-kernel@lists.infradead.org" On Wed, Jan 15, 2014 at 03:19:27PM +0800, Dong Aisheng wrote: > On Mon, Jan 13, 2014 at 8:04 PM, Peter Zijlstra wrote: > > On Thu, Dec 26, 2013 at 03:58:20PM +0800, Dong Aisheng wrote: > >> > It's strange that this issue did not happen on kernel 3.10.17 with the same > >> > code. And looking at the code, before call spin_lock we already disable the mmc > >> > controller irq, per on my understanding, the deadlock given by lockdep may not > >> > be able to happen(pls fix me if wrong). > >> > May the lockdep not track the specific irq disable? > >> > Copy lockdep guy to comment. > > > > No, lockdep also doesn't know only that one line can take this lock. > > Lockdep only knows a lock is taken from IRQ context, and disabling one > > line still allows IRQs to happen and therefore it yells. > > Okay, thanks for the information. > If that, kernel 3.10.17 has the same code, do you know why it does not trigger > such lockdep error? No idea; there haven't really been big lockdep changes recently.