linux-kernel - Re: [PATCH] mtd: spi-nor: use is_power_of

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Message-ID: <20210308090126.y3scr752sdm6oi5e@ti.com>
Date:   Mon, 8 Mar 2021 14:31:28 +0530
From:   Pratyush Yadav <p.yadav@...com>
To:     Michael Walle <michael@...le.cc>
CC:     <linux-mtd@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
        Tudor Ambarus <tudor.ambarus@...rochip.com>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>
Subject: Re: [PATCH] mtd: spi-nor: use is_power_of_2()

On 06/03/21 12:45AM, Michael Walle wrote:
> There is already a function to check if an integer is a power of 2. Use
> it.
> 
> Signed-off-by: Michael Walle <michael@...le.cc>
> ---
>  drivers/mtd/spi-nor/core.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 0522304f52fa..4a315cb1c4db 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2336,11 +2336,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>  		 * If page_size is a power of two, the offset can be quickly
>  		 * calculated with an AND operation. On the other cases we
>  		 * need to do a modulus operation (more expensive).
> -		 * Power of two numbers have only one bit set and we can use
> -		 * the instruction hweight32 to detect if we need to do a
> -		 * modulus (do_div()) or not.
>  		 */
> -		if (hweight32(nor->page_size) == 1) {
> +		if (is_power_of_2(nor->page_size)) {
>  			page_offset = addr & (nor->page_size - 1);
>  		} else {
>  			uint64_t aux = addr;

Reviewed-by: Pratyush Yadav <p.yadav@...com>

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.