Re: [PATCH v2 21/26] media: i2c: st-mipid02: Use the correct div function

From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Ricardo Ribalda <ribalda@chromium.org>
Cc: Martin Tuma <martin.tuma@digiteqautomotive.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
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	Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
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Subject: Re: [PATCH v2 21/26] media: i2c: st-mipid02: Use the correct div function
Date: Wed, 24 Apr 2024 18:22:13 +0000	[thread overview]
Message-ID: <ZilN1VBduFcqNBbr@kekkonen.localdomain> (raw)
In-Reply-To: <20240419-fix-cocci-v2-21-2119e692309c@chromium.org>

Hi Ricardo,

On Fri, Apr 19, 2024 at 09:48:07AM +0000, Ricardo Ribalda wrote:
> link_freq does not fit in 32 bits.
> 
> Found by cocci:
> drivers/media/i2c/st-mipid02.c:329:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_s64 instead.
> 
> Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/i2c/st-mipid02.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
> index f250640729ca..93a40bfda1af 100644
> --- a/drivers/media/i2c/st-mipid02.c
> +++ b/drivers/media/i2c/st-mipid02.c
> @@ -326,7 +326,7 @@ static int mipid02_configure_from_rx_speed(struct mipid02_dev *bridge,
>  	}
>  
>  	dev_dbg(&client->dev, "detect link_freq = %lld Hz", link_freq);
> -	do_div(ui_4, link_freq);
> +	ui_4 = div64_s64(ui_4, link_freq);

These are positive numbers and ui_4 is unsigned. I'd use div64_u64()
instead. With that,

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>

>  	bridge->r.clk_lane_reg1 |= ui_4 << 2;
>  
>  	return 0;
> 

-- 
Regards,

Sakari Ailus