Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751208AbbLUGnv (ORCPT ); Mon, 21 Dec 2015 01:43:51 -0500 Received: from mail-yk0-f169.google.com ([209.85.160.169]:36039 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922AbbLUGns (ORCPT ); Mon, 21 Dec 2015 01:43:48 -0500 MIME-Version: 1.0 In-Reply-To: <1449296276-32208-1-git-send-email-yamada.masahiro@socionext.com> References: <1449296276-32208-1-git-send-email-yamada.masahiro@socionext.com> From: Wan ZongShun Date: Mon, 21 Dec 2015 14:43:27 +0800 Message-ID: Subject: Re: [PATCH] clk: let clk_disable() return immediately if clk is NULL or error To: Masahiro Yamada Cc: linux-clk@vger.kernel.org, linux-mips@linux-mips.org, linux-sh@vger.kernel.org, Haojian Zhuang , Eric Miao , Hartley Sweeten , Greg Ungerer , Ryan Mallon , Geert Uytterhoeven , Steven Miao , Simon Horman , Ralf Baechle , Hauke Mehrtens , adi-buildroot-devel@lists.sourceforge.net, Russell King , "Linux/m68k" , Roland Stigge , linux-arm-kernel , linux-kernel , Dmitry Eremin-Solenikov , Magnus Damm , John Crispin Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6417 Lines: 197 2015-12-05 14:17 GMT+08:00 Masahiro Yamada : > The clk_disable() in the common clock framework (drivers/clk/clk.c) > returns immediately if the given clk is NULL or an error pointer. > It allows drivers to call clk_disable() (and clk_disable_unprepare()) > with a clock that might be NULL or an error pointer as long as the > drivers are only used along with the common clock framework. > > Unfortunately, NULL/error checking is missing from some of non-common > clk_disable() implementations. This prevents us from completely > dropping NULL/error from callers. Let's add IS_ERR_OR_NULL(clk) > checks to all callees. > > Signed-off-by: Masahiro Yamada > --- > > arch/arm/mach-ep93xx/clock.c | 2 +- > arch/arm/mach-lpc32xx/clock.c | 3 +++ > arch/arm/mach-mmp/clock.c | 3 +++ > arch/arm/mach-sa1100/clock.c | 15 ++++++++------- > arch/arm/mach-w90x900/clock.c | 3 +++ > arch/blackfin/mach-bf609/clock.c | 3 +++ > arch/m68k/coldfire/clk.c | 4 ++++ > arch/mips/bcm63xx/clk.c | 3 +++ > arch/mips/lantiq/clk.c | 3 +++ > drivers/sh/clk/core.c | 2 +- > 10 files changed, 32 insertions(+), 9 deletions(-) > > diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c > index 39ef3b6..4e11f7d 100644 > --- a/arch/arm/mach-ep93xx/clock.c > +++ b/arch/arm/mach-ep93xx/clock.c > @@ -293,7 +293,7 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > - if (!clk) > + if (IS_ERR_OR_NULL(clk)) > return; > > spin_lock_irqsave(&clk_lock, flags); > diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c > index 661c8f4..07faac2 100644 > --- a/arch/arm/mach-lpc32xx/clock.c > +++ b/arch/arm/mach-lpc32xx/clock.c > @@ -1125,6 +1125,9 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > + if (IS_ERR_OR_NULL(clk)) > + return; > + > spin_lock_irqsave(&global_clkregs_lock, flags); > local_clk_disable(clk); > spin_unlock_irqrestore(&global_clkregs_lock, flags); > diff --git a/arch/arm/mach-mmp/clock.c b/arch/arm/mach-mmp/clock.c > index 7c6f95f..7b33122 100644 > --- a/arch/arm/mach-mmp/clock.c > +++ b/arch/arm/mach-mmp/clock.c > @@ -67,6 +67,9 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > + if (IS_ERR_OR_NULL(clk)) > + return; > + > WARN_ON(clk->enabled == 0); > > spin_lock_irqsave(&clocks_lock, flags); > diff --git a/arch/arm/mach-sa1100/clock.c b/arch/arm/mach-sa1100/clock.c > index cbf53bb..ea103fd 100644 > --- a/arch/arm/mach-sa1100/clock.c > +++ b/arch/arm/mach-sa1100/clock.c > @@ -85,13 +85,14 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > - if (clk) { > - WARN_ON(clk->enabled == 0); > - spin_lock_irqsave(&clocks_lock, flags); > - if (--clk->enabled == 0) > - clk->ops->disable(clk); > - spin_unlock_irqrestore(&clocks_lock, flags); > - } > + if (IS_ERR_OR_NULL(clk)) > + return; > + > + WARN_ON(clk->enabled == 0); > + spin_lock_irqsave(&clocks_lock, flags); > + if (--clk->enabled == 0) > + clk->ops->disable(clk); > + spin_unlock_irqrestore(&clocks_lock, flags); > } > EXPORT_SYMBOL(clk_disable); > > diff --git a/arch/arm/mach-w90x900/clock.c b/arch/arm/mach-w90x900/clock.c > index 2c371ff..90ec250 100644 > --- a/arch/arm/mach-w90x900/clock.c > +++ b/arch/arm/mach-w90x900/clock.c > @@ -46,6 +46,9 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > + if (IS_ERR_OR_NULL(clk)) > + return; Looks good for w90x900 platform. Acked-by: Wan Zongshun > + > WARN_ON(clk->enabled == 0); > > spin_lock_irqsave(&clocks_lock, flags); > diff --git a/arch/blackfin/mach-bf609/clock.c b/arch/blackfin/mach-bf609/clock.c > index 3783058..fed8015 100644 > --- a/arch/blackfin/mach-bf609/clock.c > +++ b/arch/blackfin/mach-bf609/clock.c > @@ -97,6 +97,9 @@ EXPORT_SYMBOL(clk_enable); > > void clk_disable(struct clk *clk) > { > + if (IS_ERR_OR_NULL(clk)) > + return; > + > if (clk->ops && clk->ops->disable) > clk->ops->disable(clk); > } > diff --git a/arch/m68k/coldfire/clk.c b/arch/m68k/coldfire/clk.c > index fddfdcc..eb0e8c1 100644 > --- a/arch/m68k/coldfire/clk.c > +++ b/arch/m68k/coldfire/clk.c > @@ -101,6 +101,10 @@ EXPORT_SYMBOL(clk_enable); > void clk_disable(struct clk *clk) > { > unsigned long flags; > + > + if (IS_ERR_OR_NULL(clk)) > + return; > + > spin_lock_irqsave(&clk_lock, flags); > if ((--clk->enabled == 0) && clk->clk_ops) > clk->clk_ops->disable(clk); > diff --git a/arch/mips/bcm63xx/clk.c b/arch/mips/bcm63xx/clk.c > index 6375652..d6a39bf 100644 > --- a/arch/mips/bcm63xx/clk.c > +++ b/arch/mips/bcm63xx/clk.c > @@ -326,6 +326,9 @@ EXPORT_SYMBOL(clk_enable); > > void clk_disable(struct clk *clk) > { > + if (IS_ERR_OR_NULL(clk)) > + return; > + > mutex_lock(&clocks_mutex); > clk_disable_unlocked(clk); > mutex_unlock(&clocks_mutex); > diff --git a/arch/mips/lantiq/clk.c b/arch/mips/lantiq/clk.c > index a0706fd..c8d87b1 100644 > --- a/arch/mips/lantiq/clk.c > +++ b/arch/mips/lantiq/clk.c > @@ -130,6 +130,9 @@ EXPORT_SYMBOL(clk_enable); > > void clk_disable(struct clk *clk) > { > + if (IS_ERR_OR_NULL(clk)) > + return; > + > if (unlikely(!clk_good(clk))) > return; > > diff --git a/drivers/sh/clk/core.c b/drivers/sh/clk/core.c > index be56b22..3dd20cf 100644 > --- a/drivers/sh/clk/core.c > +++ b/drivers/sh/clk/core.c > @@ -252,7 +252,7 @@ void clk_disable(struct clk *clk) > { > unsigned long flags; > > - if (!clk) > + if (IS_ERR_OR_NULL(clk)) > return; > > spin_lock_irqsave(&clock_lock, flags); > -- > 1.9.1 > -- --- Vincent Wan(Zongshun) www.mcuos.com -- 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/