Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754063AbaDDSUn (ORCPT ); Fri, 4 Apr 2014 14:20:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:63363 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753722AbaDDSUl convert rfc822-to-8bit (ORCPT ); Fri, 4 Apr 2014 14:20:41 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,796,1389772800"; d="scan'208";a="507148323" From: "Du, Wenkai" To: "Westerberg, Mika" CC: "linux-i2c@vger.kernel.org" , Wolfram Sang , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] i2c-designware: Mask interrupts during i2c controller enable Thread-Topic: [PATCH] i2c-designware: Mask interrupts during i2c controller enable Thread-Index: Ac9QJwrpXJhe4Vv7Q76dkBKVgbE+4AARZeWAAA7Jh9A= Date: Fri, 4 Apr 2014 18:20:39 +0000 Message-ID: <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70F8B@ORSMSX109.amr.corp.intel.com> References: <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70E1F@ORSMSX109.amr.corp.intel.com> <20140404181613.GB19349@intel.com> In-Reply-To: <20140404181613.GB19349@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.139] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mika, In current driver implementation, I2c controller is enabled, then disabled every time inside i2c_dw_xfer. So I think the interrupt masking should be done inside i2c_dw_xfer_init, where the controller is enabled. i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { ... /* start the transfers */ i2c_dw_xfer_init(dev); ... /* * We must disable the adapter before unlocking the &dev->lock mutex * below. Otherwise the hardware might continue generating interrupts * which in turn causes a race condition with the following transfer. * Needs some more investigation if the additional interrupts are * a hardware bug or this driver doesn't handle them correctly yet. */ __i2c_dw_enable(dev, false); ... } Thanks, Wenkai -----Original Message----- From: Westerberg, Mika Sent: Friday, April 04, 2014 11:16 AM To: Du, Wenkai Cc: linux-i2c@vger.kernel.org; Wolfram Sang; linux-kernel@vger.kernel.org Subject: Re: [PATCH] i2c-designware: Mask interrupts during i2c controller enable On Fri, Apr 04, 2014 at 08:05:23PM +0300, Du, Wenkai wrote: > diff --git a/drivers/i2c/busses/i2c-designware-core.c > b/drivers/i2c/busses/i2c-designware-core.c > index 14c4b30..71a3fa9 100644 > --- a/drivers/i2c/busses/i2c-designware-core.c > +++ b/drivers/i2c/busses/i2c-designware-core.c > @@ -417,6 +417,9 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) > */ > dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR); > > + /* disable interrupts */ > + i2c_dw_disable_int(dev); > + Please move this to i2c_dw_init() as I previously commented. This can only happen once the controller comes out of reset (either boot, or resume from system sleep). > /* Enable the adapter */ > __i2c_dw_enable(dev, true); > > -- > 1.7.9.5 -- 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/