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Subject: Re: [PATCH 2/2] mtd: spi-nor: enable lock interface for macronix
 chips
From:   Ivan Mikhaylov <i.mikhaylov@yadro.com>
To:     Rasmus Villemoes <rasmus.villemoes@prevas.dk>
CC:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        "Vignesh Raghavendra" <vigneshr@ti.com>,
        <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Date:   Tue, 1 Sep 2020 17:06:59 +0300
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References: <20200812151818.16699-1-i.mikhaylov@yadro.com>
         <20200812151818.16699-3-i.mikhaylov@yadro.com>
         <ae094597-e57e-dff1-f897-bf3cc75f5511@prevas.dk>
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On Mon, 2020-08-31 at 12:55 +0200, Rasmus Villemoes wrote:
> On 12/08/2020 17.18, Ivan Mikhaylov wrote:
> > Add locks for whole macronix chip series with BP0-2 and BP0-3 bits.
> > 
> > Tested with mx25l51245g(BP0-3).
> 
> Hmm. I've tried adding support for locking on Macronix to U-Boot
> (
> https://patchwork.ozlabs.org/project/uboot/patch/20200326114257.1782-3-rasmus.villemoes@prevas.dk/
> ),
> but that was quite a bit more involved than this. Note in particular the
> first part of my commit message:
> 
>   Macronix chips implements locking in (power-of-two multiple of) 64K
>   blocks, not as a fraction of the chip's size.
> 
> At least, that was true for the chip I was interested in and the few
> others whose data sheets I grabbed to double-check. So I'm a bit
> skeptical that this can work out-of-the-box without introducing a new
> struct spi_nor_locking_ops.
> 
> Rasmus

Rasmus, but there is already locking of power-of-two as I see from the code,
I'll double check on hw. Also compared documentation n25q512ax3(micron, which
HAS_LOCK) to mx25l25635e(macronix) and they have same block protection table
bits for example. I'd be glad to hear from maintainers on this spot.

Thanks.