Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754213AbbBFBfc (ORCPT ); Thu, 5 Feb 2015 20:35:32 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:52971 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751093AbbBFBfa (ORCPT ); Thu, 5 Feb 2015 20:35:30 -0500 Message-ID: <54D41A60.8040702@codeaurora.org> Date: Thu, 05 Feb 2015 17:35:28 -0800 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Russell King - ARM Linux CC: Sylwester Nawrocki , Tomeu Vizoso , Paul Walmsley , Tony Lindgren , linux-kernel@vger.kernel.org, Mike Turquette , linux-omap@vger.kernel.org, Javier Martinez Canillas , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v13 3/6] clk: Make clk API return per-user struct clk instances References: <1422011024-32283-1-git-send-email-tomeu.vizoso@collabora.com> <1422011024-32283-4-git-send-email-tomeu.vizoso@collabora.com> <54D3C803.30706@samsung.com> <54D3CD6A.1010209@codeaurora.org> <54D3EB29.4090007@codeaurora.org> <20150206004210.GB8670@n2100.arm.linux.org.uk> In-Reply-To: <20150206004210.GB8670@n2100.arm.linux.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2349 Lines: 52 On 02/05/15 16:42, Russell King - ARM Linux wrote: > On Thu, Feb 05, 2015 at 02:14:01PM -0800, Stephen Boyd wrote: >> Actually we can bury the __clk_create_clk() inside >> __of_clk_get_from_provider(). We should also move __clk_get() into there >> because right now we have a hole where whoever calls >> of_clk_get_from_provider() never calls __clk_get() on the clk, leading >> to possible badness. v2 coming soon. > There's some other issues here too... > > sound/soc/kirkwood/kirkwood-i2s.c: > > priv->clk = devm_clk_get(&pdev->dev, np ? "internal" : NULL); > ... > priv->extclk = devm_clk_get(&pdev->dev, "extclk"); > if (IS_ERR(priv->extclk)) { > ... > } else { > if (priv->extclk == priv->clk) { > devm_clk_put(&pdev->dev, priv->extclk); > priv->extclk = ERR_PTR(-EINVAL); > } else { > dev_info(&pdev->dev, "found external clock\n"); > clk_prepare_enable(priv->extclk); > soc_dai = kirkwood_i2s_dai_extclk; > } > > It should be fine provided your "trick" is only done for DT clocks, > but not for legacy - with legacy, a NULL in the clkdev tables will > match both these requests, hence the need to compare the clk_get() > return value to tell whether we get the same clock. > Are we still talking about of_clk_get_from_provider()? Or are we talking about comparing struct clk pointers? From what I can tell this code is now broken because we made all clk getting functions (there's quite a few...) return unique pointers every time they're called. It seems that the driver wants to know if extclk and clk are the same so it can do something differently in kirkwood_set_rate(). Do we need some sort of clk_equal(struct clk *a, struct clk *b) function for drivers like this? Also, even on DT this could fail if the DT author made internal and extclk map to the same clock provider and cell. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- 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/