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Subject: Re: [PATCH 3/3] mtd: spi-nor: Add USE_FSR flag for n25q* entries
To:     <Tudor.Ambarus@microchip.com>
CC:     <miquel.raynal@bootlin.com>, <richard@nod.at>,
        <Ashish.Kumar@nxp.com>, <linux-mtd@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <john.garry@huawei.com>
References: <20191205065935.5727-1-vigneshr@ti.com>
 <20191205065935.5727-4-vigneshr@ti.com>
 <2d931347-d927-4674-86ff-7eb285624bfc@microchip.com>
From:   Vignesh Raghavendra <vigneshr@ti.com>
Message-ID: <fec29113-e048-bd47-595e-3d1f6e3955e0@ti.com>
Date:   Thu, 12 Dec 2019 13:01:51 +0530
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Hi Tudor,

On 10/12/19 10:11 pm, Tudor.Ambarus@microchip.com wrote:
> Hi, Vignesh,
> 
> On 12/5/19 8:59 AM, Vignesh Raghavendra wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> Add USE_FSR flag to all variants of n25q entries that support Flag Status
>> Register.
> 
> On a first look, all Micron flashes define the Flag Status Register. Do you know
> if there are any Micron flash that don't support FSR? If not, would you be
> interested in doing some documentation work to check this?
> 

n25q and mt25 series support FSR but older m25p/m45p parts don't have
FSR.  I don't know any easy way of finding out if flash part is m25p type.

> I think we can do this more generic, always set SNOR_F_USE_FSR for micron
> flashes, like below. More, if FSR is specific just for Micron, we can get rid of
> the USE_FSR flag too.
> 

AFAIK, FSR is definitely Micron specific (other flash vendors have
different registers/bits providing similar information though).


> Thanks, Vignesh.
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index f4afe123e9dc..fe10beea60c3 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -4595,7 +4595,7 @@ static void sst_set_default_init(struct spi_nor *nor)
> 
>  static void st_micron_set_default_init(struct spi_nor *nor)
>  {
> -       nor->flags |= SNOR_F_HAS_LOCK;
> +       nor->flags |= SNOR_F_HAS_LOCK | SNOR_F_USE_FSR;
>         nor->params.quad_enable = NULL;
>         nor->params.set_4byte = st_micron_set_4byte;
>  }
> 

-- 
Regards
Vignesh