2022-05-13 15:37:59

by Michael Walle

Subject: Re: [PATCH] mtd: spi-nor: Support Dual and Quad Read on Macronix mx25u25635f

Hi,

Am 2022-05-13 11:47, schrieb Alexander A Sverdlin:
> From: Alexander Sverdlin <[email protected]>
>
> 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.

Please post an SFDP dump of this flash [1].

-michael

[1]
https://lore.kernel.org/linux-mtd/[email protected]/

2022-05-14 03:42:38

by Alexander Sverdlin

Subject: Re: [PATCH] mtd: spi-nor: Support Dual and Quad Read on Macronix mx25u25635f

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/[email protected]/

> Please post an SFDP dump of this flash [1].

>xxd -p /sys/bus/spi/devices/spi0.0/sfdp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>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.

2022-05-14 03:59:54

by Michael Walle

Subject: Re: [PATCH] mtd: spi-nor: Support Dual and Quad Read on Macronix mx25u25635f

Hi,

Am 2022-05-13 18:09, schrieb Alexander Sverdlin:
>>> 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/[email protected]/

That doesn't seem to be the case for your flash. The quad and
dual flags you've added, will enable SFDP parsing anyway. So
instead of adding these flags, just adding PARSE_SFDP should
work, too. We still have to keep the SPI_NOR_4B_OPCODES.

>> Please post an SFDP dump of this flash [1].

Thanks.

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

That's the 4BAIT table.


> ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
> ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
> ffff002050169df9c06485cbffffffffffff

-michael