Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754544AbaDFR62 (ORCPT ); Sun, 6 Apr 2014 13:58:28 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:33869 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754178AbaDFR60 (ORCPT ); Sun, 6 Apr 2014 13:58:26 -0400 Date: Sun, 6 Apr 2014 18:58:18 +0100 From: One Thousand Gnomes To: "Westerberg, Mika" Cc: "Du, Wenkai" , "linux-i2c@vger.kernel.org" , Wolfram Sang , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] i2c-designware: Mask interrupts during i2c controller enable Message-ID: <20140406185818.3aaca03d@alan.etchedpixels.co.uk> In-Reply-To: <20140405061316.GF19349@intel.com> References: <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70E1F@ORSMSX109.amr.corp.intel.com> <20140404181613.GB19349@intel.com> <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70F8B@ORSMSX109.amr.corp.intel.com> <20140404184232.GC19349@intel.com> <7286EAF50D3F4E4AADE7FEECEBF8B5A537A71351@ORSMSX109.amr.corp.intel.com> <20140405061316.GF19349@intel.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 5 Apr 2014 09:13:16 +0300 "Westerberg, Mika" wrote: > On Sat, Apr 05, 2014 at 12:54:33AM +0300, Du, Wenkai wrote: > > >Interrupt masking is done already after each transaction. > > > > At end of transfer, the code uses __i2c_dw_enable(dev, false) to disable > > adapter. This function doesn't mask interrupts. There is another function > > i2c_dw_disable that masks and clears interrupts. This could be used, but > > that means we need to fix in 2 places: > > Please check i2c_dw_isr() and tell me in which code path interrupts are not > getting masked. Or am I missing something fundamental here? > > In case of abort, we mask interrupts. Also whenever the transaction > completes we mask interrupts (in i2c_dw_xfer_msg()). Well actually you mask the IRQ at some point after the function returns if the bus allows the write to be posted. As i2c_dw_isr can then exit the IRQ handler before the write completes I suspect you have a race ? Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/