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

[Han Xu]

The link is the first version, please check the one pushed in l2-mtd
repo. Thanks.

On Thu, Jul 23, 2015 at 10:41 AM, Alexander Stein
<alexander.stein at systec-electronic.com> wrote:
> 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
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> alexander.stein at systec-electronic.com
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