[PATCH v2] clk: let clk_disable() return immediately if clk is NULL or error

Masahiro Yamada
2016-04-05T01:51:23Z

The clk_disable() in the common clock framework (drivers/clk/clk.c)
returns immediately if a given clk is NULL or an error pointer. It
allows clock consumers to call clk_disable() without IS_ERR_OR_NULL
checking if drivers are only used 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 checking from callers. Let's make it tree-wide
consistent by adding IS_ERR_OR_NULL(clk) to all callees.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Wan Zongshun <mcuos.com@gmail.com>
---

Stephen,

This patch has been unapplied for a long time.

Please let me know if there is something wrong with this patch.

Thanks,

Changes in v2:
- Rebase on Linux 4.6-rc1

arch/arm/mach-ep93xx/clock.c | 2 +-
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 +-
9 files changed, 29 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-mmp/clock.c b/arch/arm/mach-mmp/clock.c
index ac6633d..39ad3896 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;
+
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 92863e3..9978fa4 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