diff mbox series

[v2,01/18] media: i2c: rdamc21: Fix warning on u8 cast

Message ID 20210315131512.133720-2-jacopo+renesas@jmondi.org
State Accepted
Commit 5f58ac04f36e32507d8f60fd47266ae2a60a2fa8
Headers show
Series media: gmsl: Reliability improvement | expand

Commit Message

Jacopo Mondi March 15, 2021, 1:14 p.m. UTC
Sparse reports a warning on a cast to u8 of a 16 bits constant.

drivers/media/i2c/rdacm21.c:348:62: warning: cast truncates bits
from constant value (300a becomes a)

Even if the behaviour is intended, silence the sparse warning replacing
the cast with a bitwise & operation.

Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/media/i2c/rdacm21.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Kieran Bingham March 15, 2021, 3:27 p.m. UTC | #1
Hi Jacopo,

On 15/03/2021 13:14, Jacopo Mondi wrote:
> Sparse reports a warning on a cast to u8 of a 16 bits constant.
> 
> drivers/media/i2c/rdacm21.c:348:62: warning: cast truncates bits
> from constant value (300a becomes a)
> 
> Even if the behaviour is intended, silence the sparse warning replacing
> the cast with a bitwise & operation.
> 
> Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Sounds good to me.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

> ---
>  drivers/media/i2c/rdacm21.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> index dcc21515e5a4..179d107f494c 100644
> --- a/drivers/media/i2c/rdacm21.c
> +++ b/drivers/media/i2c/rdacm21.c
> @@ -345,7 +345,7 @@ static int ov10640_initialize(struct rdacm21_device *dev)
>  	/* Read OV10640 ID to test communications. */
>  	ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR, OV490_SCCB_SLAVE_READ);
>  	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH, OV10640_CHIP_ID >> 8);
> -	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, (u8)OV10640_CHIP_ID);
> +	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, OV10640_CHIP_ID & 0xff);
>  
>  	/* Trigger SCCB slave transaction and give it some time to complete. */
>  	ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);
>
Laurent Pinchart March 15, 2021, 9:35 p.m. UTC | #2
Hi Jacopo,

Thank you for the patch.

On Mon, Mar 15, 2021 at 02:14:55PM +0100, Jacopo Mondi wrote:
> Sparse reports a warning on a cast to u8 of a 16 bits constant.
> 
> drivers/media/i2c/rdacm21.c:348:62: warning: cast truncates bits
> from constant value (300a becomes a)
> 
> Even if the behaviour is intended, silence the sparse warning replacing
> the cast with a bitwise & operation.
> 
> Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/media/i2c/rdacm21.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> index dcc21515e5a4..179d107f494c 100644
> --- a/drivers/media/i2c/rdacm21.c
> +++ b/drivers/media/i2c/rdacm21.c
> @@ -345,7 +345,7 @@ static int ov10640_initialize(struct rdacm21_device *dev)
>  	/* Read OV10640 ID to test communications. */
>  	ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR, OV490_SCCB_SLAVE_READ);
>  	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH, OV10640_CHIP_ID >> 8);
> -	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, (u8)OV10640_CHIP_ID);
> +	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, OV10640_CHIP_ID & 0xff);
>  
>  	/* Trigger SCCB slave transaction and give it some time to complete. */
>  	ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);
diff mbox series

Patch

diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
index dcc21515e5a4..179d107f494c 100644
--- a/drivers/media/i2c/rdacm21.c
+++ b/drivers/media/i2c/rdacm21.c
@@ -345,7 +345,7 @@  static int ov10640_initialize(struct rdacm21_device *dev)
 	/* Read OV10640 ID to test communications. */
 	ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR, OV490_SCCB_SLAVE_READ);
 	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH, OV10640_CHIP_ID >> 8);
-	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, (u8)OV10640_CHIP_ID);
+	ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, OV10640_CHIP_ID & 0xff);
 
 	/* Trigger SCCB slave transaction and give it some time to complete. */
 	ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);