Re: [PATCH] clk: let clk_disable() return immediately if clk is NULL or error
From: Wan ZongShun
Date: Mon Dec 21 2015 - 01:44:28 EST
2015-12-05 14:17 GMT+08:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>:
> 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 <yamada.masahiro@xxxxxxxxxxxxx>
> ---
>
> 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 <mcuos.com@xxxxxxxxx>
> +
> 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
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