From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758804Ab2CTHqH (ORCPT ); Tue, 20 Mar 2012 03:46:07 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:31738 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758130Ab2CTHqF (ORCPT ); Tue, 20 Mar 2012 03:46:05 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6654"; a="173958089" Message-ID: <348585ed29fb3ff171267c03658e6c0d.squirrel@www.codeaurora.org> In-Reply-To: <20120320071957.GH3852@pengutronix.de> References: <1332214706-675-1-git-send-email-skannan@codeaurora.org> <20120320071957.GH3852@pengutronix.de> Date: Tue, 20 Mar 2012 00:46:04 -0700 (PDT) Subject: Re: [PATCH 1/2] clk: Fix error handling in fixed clock hardware type register fn From: "Saravana Kannan" To: "Sascha Hauer" Cc: "Saravana Kannan" , "Mike Turquette" , "Arnd Bergman" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, "Andrew Lunn" , "Rob Herring" , "Russell King" , "Jeremy Kerr" , "Thomas Gleixner" , "Paul Walmsley" , "Shawn Guo" , "Jamie Iles" , "Richard Zhao" , "Magnus Damm" , "Mark Brown" , "Linus Walleij" , "Stephen Boyd" , "Amit Kucheria" , "Deepak Saxena" , "Grant Likely" User-Agent: SquirrelMail/1.4.17 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, March 20, 2012 12:19 am, Sascha Hauer wrote: > On Mon, Mar 19, 2012 at 08:38:25PM -0700, Saravana Kannan wrote: >> If memory allocation for the parents array or the parent string fails, >> then >> fail the registration immediately instead of calling clk_register and >> hoping it fails there. >> >> Return -ENOMEM on failure. >> >> Signed-off-by: Saravana Kannan >> Cc: Mike Turquette >> Cc: Andrew Lunn >> Cc: Rob Herring >> Cc: Russell King >> Cc: Jeremy Kerr >> Cc: Thomas Gleixner >> Cc: Arnd Bergman >> Cc: Paul Walmsley >> Cc: Shawn Guo >> Cc: Sascha Hauer >> Cc: Jamie Iles >> Cc: Richard Zhao >> Cc: Saravana Kannan >> Cc: Magnus Damm >> Cc: Mark Brown >> Cc: Linus Walleij >> Cc: Stephen Boyd >> Cc: Amit Kucheria >> Cc: Deepak Saxena >> Cc: Grant Likely >> --- >> There are still some memory free issues when clk_register() fails, but I >> will >> fix it when I fixed the other register() fns to return ENOMEM of alloc >> failure instead of a NULL. >> >> drivers/clk/clk-fixed-rate.c | 10 +++++++--- >> 1 files changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c >> index 90c79fb..6423ae9 100644 >> --- a/drivers/clk/clk-fixed-rate.c >> +++ b/drivers/clk/clk-fixed-rate.c >> @@ -61,22 +61,26 @@ struct clk *clk_register_fixed_rate(struct device >> *dev, const char *name, >> parent_names = kmalloc(sizeof(char *), GFP_KERNEL); >> >> if (! parent_names) >> - goto out; >> + goto fail_ptr; >> >> len = sizeof(char) * strlen(parent_name); >> >> parent_names[0] = kmalloc(len, GFP_KERNEL); >> >> if (!parent_names[0]) >> - goto out; >> + goto fail_str; >> >> strncpy(parent_names[0], parent_name, len); >> } > > It's easier to add a char *parent to struct clk_fixed and pass it to > clk_register with &fixed->parent. This saves you a kmalloc call and > makes the error path simpler. It's the same way already done in the > divider. I thought about that since I saw the same was done for gated and divider (I think). Here is my guess at Mike's reasoning for this: Gated and divider clocks have to have a parent. There's nothing to gate otherwise. But fixed rate clocks might not have a parent. It could be XO's or PLLs running off of always on XOs not controlled by the SoC. So, it's arguable to not have a parent. I don't have a strong opinion on this -- since Mike took the time to write it, it left it to his subjective preference. I sent this patch first since it was around the place I was cleaning up. I didn't want to actually just shuffle around a bug. As I mentioned, this patch still leaves a bug open -- what if clk_register() fails. I plan to fix that once my two patches are picked up (hopefully). Thanks, Saravana -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.