[PATCH] i2c: reduce parent checking to a NOOP in non-I2C_MUX case

[PATCH] i2c: reduce parent checking to a NOOP in non-I2C_MUX case

[Phil Carmody]

In 0826374 - i2c: Multiplexed I2C bus core support
core i2c code increased in size and complexity even when I2C_MUX
wasn't selected.

Turning this check into a constant NULL in the n case lets the
client functions in be simplified too, not needing to include
never-called calls to the mux-specific helpers.

Signed-off-by: Phil Carmody <phil.carmody-GrGkmOP51GdLN7c7dRTbYkEOCMrvLtNR@public.gmane.org>
---
 include/linux/i2c.h |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e988fa9..b3c4b8d 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -447,11 +447,13 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 static inline struct i2c_adapter *
 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 {
+#if IS_ENABLED(I2C_MUX)
 	struct device *parent = adapter->dev.parent;
 
 	if (parent != NULL && parent->type == &i2c_adapter_type)
 		return to_i2c_adapter(parent);
 	else
+#endif
 		return NULL;
 }
 
-- 
1.7.9.5

Re: [PATCH] i2c: reduce parent checking to a NOOP in non-I2C_MUX case

[Wolfram Sang]

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On Wed, Jun 26, 2013 at 10:56:35AM +0300, Phil Carmody wrote:
> In 0826374 - i2c: Multiplexed I2C bus core support
> core i2c code increased in size and complexity even when I2C_MUX
> wasn't selected.
> 
> Turning this check into a constant NULL in the n case lets the
> client functions in be simplified too, not needing to include
> never-called calls to the mux-specific helpers.
> 
> Signed-off-by: Phil Carmody <phil.carmody-GrGkmOP51GdLN7c7dRTbYkEOCMrvLtNR@public.gmane.org>

Not my favourite style to have #endif in the code block, but good
enough. Applied to for-next, thanks!

> ---
>  include/linux/i2c.h |    2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index e988fa9..b3c4b8d 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -447,11 +447,13 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
>  static inline struct i2c_adapter *
>  i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
>  {
> +#if IS_ENABLED(I2C_MUX)
>  	struct device *parent = adapter->dev.parent;
>  
>  	if (parent != NULL && parent->type == &i2c_adapter_type)
>  		return to_i2c_adapter(parent);
>  	else
> +#endif
>  		return NULL;
>  }
>  
> -- 
> 1.7.9.5
> 

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