Re: [PATCH 1/1] mtd: fsl-quadspi: Add mutex for accessing different SPI-NOR devices

[Alexander Stein <alexander.stein@systec-electronic.com>]

Hi Han,

On Thursday 23 July 2015 10:31:05, Han Xu wrote:
> I think it is the same patch
> 
>  http://patchwork.ozlabs.org/patch/429631/

Yep. They are more or less the same. I didn't know about this.
I lack the include though, which seems the right thing to do.

But I see a problem in your case:
> @@ -751,6 +753,8 @@ static int fsl_qspi_prep(struct spi_nor *nor, enum 
spi_nor_ops ops)
>  	struct fsl_qspi *q = nor->priv;
>  	int ret;
>  
> +	mutex_lock(&q->lock);
> +
>  	ret = clk_enable(q->clk_en);
>  	if (ret)
>  		return ret;

I see a problem here. If one of those clk_enable fails, you return with the 
mutex still being locked. That's why I lock/unlock the mutex the last/first in 
prepare/unprepare.

Best regards,
Alexander
-- 
Dipl.-Inf. Alexander Stein
SYS TEC electronic GmbH
alexander.stein@systec-electronic.com

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