RE: [PATCHv2] mfd: twl4030: clarify the return value for read andwrite

[Gadiyar, Anand]

Amit Kucheria wrote:
> Infact, we can just return -1 so that caller knows for sure that all messages
> were not tranferred. Please consider fixed patch instead.
> 
> We should be checking if all the messages were tranferred or not. And return
> -1 for failure. Currently we return success (0) even if none of messages were
> transferred successfully.
> 
> Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx>
> ---
>  drivers/mfd/twl4030-core.c |   25 +++++++++++++++++--------
>  1 files changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
> index 56f1de5..8f9ba79 100644
> --- a/drivers/mfd/twl4030-core.c
> +++ b/drivers/mfd/twl4030-core.c
> @@ -292,10 +292,14 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
>  	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
>  	mutex_unlock(&twl->xfer_lock);
>  
> -	/* i2cTransfer returns num messages.translate it pls.. */
> -	if (ret >= 0)
> -		ret = 0;
> -	return ret;
> +	/* i2c_transfer returns number of messages transferred */
> +	if (ret != 1) {
> +		pr_err("%s: i2c_write failed to transfer all messages\n",
> +			DRIVER_NAME);
> +		return -1;
> +	} else {
> +		return 0;
> +	}
>  }
>  EXPORT_SYMBOL(twl4030_i2c_write);
>  
> @@ -344,10 +348,15 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
>  	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
>  	mutex_unlock(&twl->xfer_lock);
>  
> -	/* i2cTransfer returns num messages.translate it pls.. */
> -	if (ret >= 0)
> -		ret = 0;
> -	return ret;
> +	/* i2c_transfer returns number of messages transferred */
> +	if (ret != 2) {
> +		pr_err("%s: i2c_read failed to transfer all messages\n",
> +			DRIVER_NAME);
> +		return -1;
> +	}
> +	else {
> +		return 0;
> +	}

The else clause should be on the same line as the brace closing the if clause.
like you did above

So says Documentation/CodingStyle.

- Anand
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