Re: [PATCH v2 2/6] mtd: spi-nor: add erase die (chip) capability

From: Michael Walle <michael@walle.cc>
To: Tudor Ambarus <tudor.ambarus@linaro.org>
Cc: Fabio Estevam <festevam@denx.de>,
	Takahiro Kuwano <Takahiro.Kuwano@infineon.com>,
	pratyush@kernel.org, linux-mtd@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, bacem.daassi@infineon.com,
	miquel.raynal@bootlin.com, richard@nod.at
Subject: Re: [PATCH v2 2/6] mtd: spi-nor: add erase die (chip) capability
Date: Mon, 06 Nov 2023 10:34:17 +0100	[thread overview]
Message-ID: <ea846bc8c214836c40c06fd875aee575@walle.cc> (raw)
In-Reply-To: <a3ccb98e-b8bd-4ea3-98c4-df429602a7ef@linaro.org>

Am 2023-11-03 14:48, schrieb Tudor Ambarus:
> On 03.11.2023 15:37, Fabio Estevam wrote:
>> On 03/11/2023 10:26, Tudor Ambarus wrote:
>> 
>>> Which version of mtd-utils are you using? I guess the flash-erase
>> 
>> mtd-utils 2.1.5
>> 
>>> utility is written in a bad way. Please use the following while I 
>>> check
>>> what flash_erase is doing:
>>> 
>>> time mtd_debug erase /dev/mtd0 0 134217728
>> 
>> "mtd_debug erase" gives the same time as well:
>> 
>> root@mcde3000a:~# time mtd_debug erase /dev/mtd0 0 134217728
>> [ 4322.114967] spi-nor spi0.0: ***** nor->reg_proto = 0x00010101
>> [ 4322.120861] spi-nor spi0.0: *****
>> [ 4322.124210] spi-nor spi0.0: ***** op.cmd.nbytes = 0x01
>> [ 4322.129478] spi-nor spi0.0: ***** op.cmd.buswidth = 0x01
>> [ 4322.134903] spi-nor spi0.0: ***** op.cmd.opcode = 0xc4
>> [ 4322.140154] spi-nor spi0.0: *****
>> [ 4322.143491] spi-nor spi0.0: ***** op.addr.nbytes = 0x04
>> [ 4322.148831] spi-nor spi0.0: ***** op.addr.buswidth = 0x01
>> [ 4322.154341] spi-nor spi0.0: ***** op.addr.buswidth = 0x0
>> [ 4322.159761] spi-nor spi0.0: *****
>> [ 4322.163098] spi-nor spi0.0: ***** op.dummy.nbytes = 0x00
>> [ 4322.168524] spi-nor spi0.0: ***** op.dummy.buswidth = 0x00
>> [ 4322.174118] spi-nor spi0.0: *****
>> [ 4322.177439] spi-nor spi0.0: ***** op.data.buswidth = 0x00
>> [ 4322.182948] spi-nor spi0.0: ***** op.data.nbytes = 0
>> [ 4439.966060] spi-nor spi0.0: ***** nor->reg_proto = 0x00010101
>> [ 4439.971920] spi-nor spi0.0: *****
>> [ 4439.975252] spi-nor spi0.0: ***** op.cmd.nbytes = 0x01
>> [ 4439.980511] spi-nor spi0.0: ***** op.cmd.buswidth = 0x01
>> [ 4439.985928] spi-nor spi0.0: ***** op.cmd.opcode = 0xc4
>> [ 4439.991174] spi-nor spi0.0: *****
>> [ 4439.994504] spi-nor spi0.0: ***** op.addr.nbytes = 0x04
>> [ 4439.999834] spi-nor spi0.0: ***** op.addr.buswidth = 0x01
>> [ 4440.005335] spi-nor spi0.0: ***** op.addr.buswidth = 0x4000000
>> [ 4440.011272] spi-nor spi0.0: *****
>> [ 4440.014604] spi-nor spi0.0: ***** op.dummy.nbytes = 0x00
>> [ 4440.020018] spi-nor spi0.0: ***** op.dummy.buswidth = 0x00
>> [ 4440.025606] spi-nor spi0.0: *****
>> [ 4440.028937] spi-nor spi0.0: ***** op.data.buswidth = 0x00
>> [ 4440.034438] spi-nor spi0.0: ***** op.data.nbytes = 0
>> Erased 134217728 bytes from address 0x00000000 in flash
>> 
>> real    3m57.384s
>> user    0m0.005s
>> sys    3m35.211s
>> 
> 
> Yep, it's strange, we'll have to check what's happening. I found my
> n25q00 flash, on my side all its 4 dice are erased in 5 sec.  SFDP
> defines how long the erase die should take, see BFPT dword 11. You can
> start with that.

Had the flash some contents or was it all-ff? Maybe the Micron flash 
will
check if all bytes are one and will skip the erase.

Die/Chip erases will take much longer most of the time and are 
comparable
to individual sector erases (as Fabio also found out). You'll probably
just save the overhead of the indivudal commands.

I've looked at the N25Q00AA datasheet and the erase time there is 153s
(typ) for *one* die.

-michael

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