From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932443AbcKHKiH (ORCPT ); Tue, 8 Nov 2016 05:38:07 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:46040 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932185AbcKHKiE (ORCPT ); Tue, 8 Nov 2016 05:38:04 -0500 DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org 3FA4F6159E Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=rnayak@codeaurora.org Message-ID: <5821AB06.4060303@codeaurora.org> Date: Tue, 08 Nov 2016 16:07:58 +0530 From: Rajendra Nayak User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Geert Uytterhoeven CC: Stephen Boyd , Michael Turquette , linux-clk , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] clk: Free struct clk allocated during clk_hw_register() References: <1478593430-23102-1-git-send-email-rnayak@codeaurora.org> <5821A331.5060405@codeaurora.org> In-Reply-To: <5821A331.5060405@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/08/2016 03:34 PM, Rajendra Nayak wrote: > > > On 11/08/2016 03:06 PM, Geert Uytterhoeven wrote: >> Hi Rajendra, >> >> On Tue, Nov 8, 2016 at 9:23 AM, Rajendra Nayak wrote: >>> With clk_hw_register() API we hide the struct clk from the caller >>> and return an int error code instead, so the caller (clk provider) >>> is not expected to use hw->clk on return. >> >> That's correct, in case of failure. > > sorry, maybe the commit text needs to be reworded. I meant 'clk_hw_register() returns > an int (not a struct clk pointer), 0 on success or an error code in case of a failure. > >> >>> Free the memory, and mark hw->clk as NULL before returning. >>> >>> Signed-off-by: Rajendra Nayak >>> --- >>> drivers/clk/clk.c | 10 +++++++++- >>> 1 file changed, 9 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c >>> index 0fb39fe..f81e4aa 100644 >>> --- a/drivers/clk/clk.c >>> +++ b/drivers/clk/clk.c >>> @@ -2628,7 +2628,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >>> */ >>> int clk_hw_register(struct device *dev, struct clk_hw *hw) >>> { >>> - return PTR_ERR_OR_ZERO(clk_register(dev, hw)); >>> + struct clk *c; >>> + >>> + c = clk_register(dev, hw); >>> + if (IS_ERR(c)) >>> + return PTR_ERR(c); >>> + >>> + __clk_free_clk(c); >>> + hw->clk = NULL; >> >> This is the success path, not the failure path (on failure, clk_register() >> has already freed the struct clk). >> Why do you free the struct clk in case of success? >> >> What am I missing? > > so with 'per-user' clks, I thought we now have one struct clk per user, allocated > when the user does a clk_get() and freed with a clk_put(), so we shouldn't ideally > need one during clk registration? > The one allocated in clk_register() is for legacy users who need to get a struct clk * > back. For users of clk_hw_register() this should not be needed, no? Looking through this a little more, I don't think we can get rid of the 'struct clk' allocations at registration time as yet. It seems to be used by clk_get_parent() at least, which does not yet do a __clk_create_clk() and relies on hw->clk -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation