Re: [PATCH] ahci: use hweight_long() to count port_map bits

[Niklas Cassel <cassel@kernel.org>]

On Wed, May 27, 2026 at 05:17:29PM +0800, kensanya@163.com wrote:
> From: TanZheng <tanzheng@kylinos.cn>
> 
> Replace the open loop used to calculate the number of set bits
> in the port mapping with the `hweight_long()` function, which
> simplifies the code without altering its functionality.
> 
> Signed-off-by: TanZheng <tanzheng@kylinos.cn>
> ---
>  drivers/ata/libahci.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index c79abdfcd7a9..15d44266c9df 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -552,11 +552,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
>  
>  	/* cross check port_map and cap.n_ports */
>  	if (port_map) {
> -		int map_ports = 0;
> -
> -		for (i = 0; i < AHCI_MAX_PORTS; i++)
> -			if (port_map & (1 << i))
> -				map_ports++;
> +		int map_ports = hweight_long(port_map);
>  
>  		/* If PI has more ports than n_ports, whine, clear
>  		 * port_map and let it be generated from n_ports.
> -- 
> 2.25.1
> 

Hello TanZheng,

Is it a coincidence that you send this the same day as Michael pointed out
the same, or was this sent as a response to Michael's email?


Kind regards,
Niklas