Re: [PATCH v2] gpio: pca953x: remove incorrect le16_to_cpu calls

[Gregory CLEMENT <gregory.clement@free-electrons.com>]

Hi Andy,
 
 On mar., juil. 18 2017, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> i2c_smbus commands handle the correct byte order for smbus
> transactions

I am not sure of this claim, I didn't find any cpu_to_lexx in the sbmus
function.

> internally. This will currently result in incorrect operation on big
> endian systems.

Did you managed to test this driver in a big endian system and to check
that with this patch the driver worked as expected?

Thanks,

Gregory


>
> Suggested-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> - add RB tag
>  drivers/gpio/gpio-pca953x.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index 4c9e21300a26..1b9dbf691ae7 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -187,10 +187,9 @@ static int pca953x_write_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
>  
>  static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
>  {
> -	__le16 word = cpu_to_le16(get_unaligned((u16 *)val));
> +	u16 word = get_unaligned((u16 *)val);
>  
> -	return i2c_smbus_write_word_data(chip->client,
> -					 reg << 1, (__force u16)word);
> +	return i2c_smbus_write_word_data(chip->client, reg << 1, word);
>  }
>  
>  static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
> @@ -241,8 +240,7 @@ static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
>  	int ret;
>  
>  	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
> -	val[0] = (u16)ret & 0xFF;
> -	val[1] = (u16)ret >> 8;
> +	put_unaligned(ret, (u16 *)val);
>  
>  	return ret;
>  }
> -- 
> 2.11.0
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com