[PATCH v3] clk: let clk_disable() return immediately if clk is NULL

From: Masahiro Yamada
Date: Wed Aug 24 2016 - 13:32:03 EST


Many of clk_disable() implementations just return for NULL pointer,
but this check is missing from some. Let's make it tree-wide
consistent. It will allow clock consumers to call clk_disable()
without NULL pointer check.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Acked-by: Greg Ungerer <gerg@xxxxxxxxxxx>
Acked-by: Wan Zongshun <mcuos.com@xxxxxxxxx>
---

I came back after a long pause.
You can see the discussion about the previous version:
https://www.linux-mips.org/archives/linux-mips/2016-04/msg00063.html


Changes in v3:
- Return only when clk is NULL. Do not take care of error pointer.

Changes in v2:
- Rebase on Linux 4.6-rc1

arch/arm/mach-mmp/clock.c | 3 +++
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 +++
5 files changed, 16 insertions(+)

diff --git a/arch/arm/mach-mmp/clock.c b/arch/arm/mach-mmp/clock.c
index ac6633d..28fe64c 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 (!clk)
+ return;
+
WARN_ON(clk->enabled == 0);

spin_lock_irqsave(&clocks_lock, flags);
diff --git a/arch/arm/mach-w90x900/clock.c b/arch/arm/mach-w90x900/clock.c
index 2c371ff..ac6fd1a 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 (!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..392a59b 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 (!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..1e3c7e9 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 (!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..b49fc9c 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 (!clk)
+ return;
+
mutex_lock(&clocks_mutex);
clk_disable_unlocked(clk);
mutex_unlock(&clocks_mutex);
--
1.9.1