linux-kernel - Re: [PATCH 1/1] mtd: spi-nor: improve macronix_quad

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Date:   Tue, 6 Dec 2016 20:01:03 +0100
From:   Marek Vasut <marek.vasut@...il.com>
To:     Cyrille Pitchen <cyrille.pitchen@...el.com>
Cc:     computersforpeace@...il.com, boris.brezillon@...e-electrons.com,
        richard@....at, linux-mtd@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] mtd: spi-nor: improve macronix_quad_enable()

On 12/06/2016 05:01 PM, Cyrille Pitchen wrote:
> The patch checks whether the Quad Enable bit is already set in the Status
> Register. If so, the function exits immediately with a successful return
> code.

Performance optimization I presume ?

Acked-by: Marek Vasut <marek.vasut@...il.com>

> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@...el.com>
> Reviewed-by: Jagan Teki <jagan@...nedev.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index da7cd69d4857..1fd32b991eb7 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1216,6 +1216,9 @@ static int macronix_quad_enable(struct spi_nor *nor)
>  	val = read_sr(nor);
>  	if (val < 0)
>  		return val;
> +	if (val & SR_QUAD_EN_MX)
> +		return 0;
> +
>  	write_enable(nor);
>  
>  	write_sr(nor, val | SR_QUAD_EN_MX);
> 


-- 
Best regards,
Marek Vasut