Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935116AbZLGNxY (ORCPT ); Mon, 7 Dec 2009 08:53:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935072AbZLGNxX (ORCPT ); Mon, 7 Dec 2009 08:53:23 -0500 Received: from smtp.nokia.com ([192.100.122.230]:29321 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935048AbZLGNxX (ORCPT ); Mon, 7 Dec 2009 08:53:23 -0500 Date: Mon, 7 Dec 2009 15:53:09 +0200 From: Eduardo Valentin To: ext Amit Kucheria Cc: Samuel Ortiz , "gadiyar@ti.com" , List Linux Kernel , List Linux Omap Subject: Re: [PATCH 1/1] mfd: twl4030: clarify the return value for read and write Message-ID: <20091207135309.GA23829@esdhcp037198.research.nokia.com> Reply-To: eduardo.valentin@nokia.com References: <5A47E75E594F054BAF48C5E4FC4B92AB0309DAC23C@dbde02.ent.ti.com> <449d505b874c236e4d0df0c1f765918386a4d58b.1260187781.git.amit.kucheria@verdurent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <449d505b874c236e4d0df0c1f765918386a4d58b.1260187781.git.amit.kucheria@verdurent.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-OriginalArrivalTime: 07 Dec 2009 13:53:13.0377 (UTC) FILETIME=[9E7A3110:01CA7744] X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2723 Lines: 80 On Mon, Dec 07, 2009 at 01:17:29PM +0100, ext Amit Kucheria wrote: > Infact, we can just return -EIO so that caller knows for sure that all > messages were not tranferred. Please consider fixed patch instead. > > We should be checking if all the messages were tranferred or not. And return > -1 for failure. Currently we return success (0) even if none of messages were > transferred successfully. > > Signed-off-by: Amit Kucheria > --- > drivers/mfd/twl4030-core.c | 24 ++++++++++++++++-------- > 1 files changed, 16 insertions(+), 8 deletions(-) > > diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c > index 56f1de5..3d2c413 100644 > --- a/drivers/mfd/twl4030-core.c > +++ b/drivers/mfd/twl4030-core.c > @@ -292,10 +292,14 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes) > ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1); > mutex_unlock(&twl->xfer_lock); > > - /* i2cTransfer returns num messages.translate it pls.. */ > - if (ret >= 0) > - ret = 0; > - return ret; > + /* i2c_transfer returns number of messages transferred */ > + if (ret != 1) { > + pr_err("%s: i2c_write failed to transfer all messages\n", > + DRIVER_NAME); > + return -EIO; How about reporting the actual error that has occurred and reported by i2c_transfer? Instead of just masking it as EIO? If i2c_transfer returns something > 0 then EIO should be right. But if returns and error code, then that error code must be reported to upper layers. > + } else { > + return 0; > + } > } > EXPORT_SYMBOL(twl4030_i2c_write); > > @@ -344,10 +348,14 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes) > ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2); > mutex_unlock(&twl->xfer_lock); > > - /* i2cTransfer returns num messages.translate it pls.. */ > - if (ret >= 0) > - ret = 0; > - return ret; > + /* i2c_transfer returns number of messages transferred */ > + if (ret != 2) { > + pr_err("%s: i2c_read failed to transfer all messages\n", > + DRIVER_NAME); > + return -EIO; dito. > + } else { > + return 0; > + } > } > EXPORT_SYMBOL(twl4030_i2c_read); > > -- > 1.6.3.3 > > -- > 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/ -- Eduardo Valentin -- 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/