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Message-ID: <d59ec4e0-3bce-2b44-1fc5-54a26fe77c7f@nokia.com>
Date:   Fri, 13 May 2022 18:09:39 +0200
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Subject: Re: [PATCH] mtd: spi-nor: Support Dual and Quad Read on Macronix
 mx25u25635f
Content-Language: en-US
To:     Michael Walle <michael@walle.cc>
Cc:     linux-mtd@lists.infradead.org,
        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>,
        linux-kernel@vger.kernel.org
References: <20220513094759.44185-1-alexander.sverdlin@nokia.com>
 <34eccc66cc75dd0ffbf8a77780b6f8a7@walle.cc>
From:   Alexander Sverdlin <alexander.sverdlin@nokia.com>
In-Reply-To: <34eccc66cc75dd0ffbf8a77780b6f8a7@walle.cc>
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Hello Michael,

>> According to datasheet both Dual and Quad Read is supported. The read test
>> shows x3.8 speed gain.
> 
> Does it have SFDP? Try adding PARSE_SFDP instead of the
> NO_SFDP_FLAGS.

Some issues with its SFDP were known:
https://patchwork.ozlabs.org/project/linux-mtd/patch/1492068234-9509-1-git-send-email-dev@kresin.me/
 
> Please post an SFDP dump of this flash [1].

>xxd -p /sys/bus/spi/devices/spi0.0/sfdp
53464450060102ff00060110300000ffc2000104100100ff84000102c000
00ffffffffffffffffffffffffffffffffffe520fbffffffff0f44eb086b
083b04bbfeffffffffff00ffffff44eb0c200f5210d800ff8749b50082d2
04d24403673830b030b0f7bdd55c4a9e29fff050f985ffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffff7f8fffff215cdcffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffff002050169df9c06485cbffffffffffff

>md5sum /sys/bus/spi/devices/spi0.0/sfdp
bc360997e729ce1f77f1ff728621d94f /sys/bus/spi/devices/spi0.0/sfdp

>cat /sys/bus/spi/devices/spi0.0/jedec_id
c22539

>cat /sys/bus/spi/devices/spi0.0/partname
mx25u25635f

>cat /sys/bus/spi/devices/spi0.0/manufacturer
macronix

-- 
Best regards,
Alexander Sverdlin.