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Date:   Tue, 10 May 2022 16:03:46 +0200
From:   Michael Walle <michael@walle.cc>
To:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Pratyush Yadav <p.yadav@ti.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
Cc:     linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] mtd: spi-nor: introduce SNOR_ID3()
In-Reply-To: <20220510140232.3519184-1-michael@walle.cc>
References: <20220510140232.3519184-1-michael@walle.cc>
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[proper subject]

Am 2022-05-10 16:02, schrieb Michael Walle:
> For support which rely solely on the SFDP data, all we need to know is 
> its
> JEDEC ID. All further information should be fetched from SFDP. For 
> this,
> introduce a SNOR_ID3() macro which should be used for all new flashes 
> with
> SFDP.
> 
> The dropped information are page size, number of sectors and sector 
> size.
> The number of sectors (together with sector size) is only used to 
> calculate
> the total flash size. In case of SFDP, this is read from there. The 
> sector
> size is also used to select a proper erase opcode. We can just keep 
> that
> one zero and the selection algorithm will select the same erase opcode;
> that is the opcode for the largest erase size (which is btw rather 
> odd..).
> The page size is also taken from SFDP. There is one exception: older 
> SFDP
> tables. These doesn't contain this data. So if there will be flashes 
> with
> that, we should assume some sane value.
> 
> Shaik, could you please re-test your w25q512nwm support with this 
> patch. I
> read through the SFDP data and it should behave exactly the same as 
> before.
> 
> Michael Walle (2):
>   mtd: spi-nor: introduce SNOR_ID3()
>   mtd: spi-nor: winbond: use SNOR_ID3() for w25q512nwm
> 
>  drivers/mtd/spi-nor/core.c    | 7 +++++--
>  drivers/mtd/spi-nor/core.h    | 9 +++++++++
>  drivers/mtd/spi-nor/winbond.c | 3 +--
>  3 files changed, 15 insertions(+), 4 deletions(-)