From: Phil Reid <preid@electromag.com.au>
To: Yong Li <sdliyong@gmail.com>,
linus.walleij@linaro.org, gnurou@gmail.com,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gpio: pca953x: Use correct u16 value for register word write
Date: Tue, 29 Mar 2016 20:06:14 +0800 [thread overview]
Message-ID: <56FA6FB6.4040003@electromag.com.au> (raw)
In-Reply-To: <1459232852-15697-1-git-send-email-sdliyong@gmail.com>
G'day Yong,
One comment below.
On 29/03/2016 2:27 PM, Yong Li wrote:
> The current implementation only uses the first byte in *val,
> the second data is always 0. Change it to *(u16 *)val
> to write the two bytes into the register
>
> Signed-off-by: Yong Li <sdliyong@gmail.com>
> ---
> drivers/gpio/gpio-pca953x.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index d0d3065..cf3d410 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -159,7 +159,7 @@ static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
> switch (chip->chip_type) {
> case PCA953X_TYPE:
> ret = i2c_smbus_write_word_data(chip->client,
> - reg << 1, (u16) *val);
> + reg << 1, *(u16 *)val);
I don't think this is safe for systems that don't support unaligned memory access.
> break;
> case PCA957X_TYPE:
> ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
>
--
Regards
Phil Reid
next prev parent reply other threads:[~2016-03-29 12:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-29 6:27 [PATCH] gpio: pca953x: Use correct u16 value for register word write Yong Li
2016-03-29 12:06 ` Phil Reid [this message]
2016-03-29 12:53 ` Yong Li
2016-03-29 14:39 ` Alexander Stein
2016-03-29 16:33 ` Phil Reid
2016-03-30 2:46 ` Yong Li
[not found] ` <CADO9-pdxpQRQQ8RFtjT6rz28GteL3u+at0EGVdNwG8VV48SGEw@mail.gmail.com>
2016-03-30 5:01 ` Yong Li
2016-03-30 5:14 ` Phil Reid
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