2021-04-08 07:40:54

by Mauro Carvalho Chehab

Subject: [PATCH 2/3] media: rdacm21: describe better a truncation

As warned by sparse:

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

the intention of the code is to get just the lowest 8 bits.
So, instead of using a typecast, use a bit and logic.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
---
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);
--
2.30.2

2021-04-08 07:55:30

by jacopo mondi

Subject: Re: [PATCH 2/3] media: rdacm21: describe better a truncation

Hi Mauro

On Thu, Apr 08, 2021 at 09:40:03AM +0200, Mauro Carvalho Chehab wrote:
> As warned by sparse:
>
> drivers/media/i2c/rdacm21.c:348:62: warning: cast truncates bits from constant value (300a becomes a)
>
> the intention of the code is to get just the lowest 8 bits.
> So, instead of using a typecast, use a bit and logic.
>
> Signed-off-by: Mauro Carvalho Chehab <[email protected]>

Please see
https://patchwork.linuxtv.org/project/linux-media/patch/[email protected]/

Whatever gets in first it's fine, so you can add my
Acked-by: Jacopo Mondi <[email protected]>
to this one too

Thanks
j

> ---
> 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);
> --
> 2.30.2
>