Re: [PATCH 2/3] mtd: rawnand: arasan: Ensure program page operations are successful

Michal Simek
2023-09-20T07:55:18Z

Hi Miquel,

On 9/12/23 16:17, Miquel Raynal wrote:
> Hi Michal,
>
> michal.simek@amd.com wrote on Tue, 12 Sep 2023 15:55:23 +0200:
>
>> Hi Miquel,
>>
>> On 9/11/23 17:52, Miquel Raynal wrote:
>>> Hi Michal,
>>>
>>> miquel.raynal@bootlin.com wrote on Mon, 17 Jul 2023 21:42:20 +0200:
>>>
>>>> The NAND core complies with the ONFI specification, which itself
>>>> mentions that after any program or erase operation, a status check
>>>> should be performed to see whether the operation was finished *and*
>>>> successful.
>>>>
>>>> The NAND core offers helpers to finish a page write (sending the
>>>> "PAGE PROG" command, waiting for the NAND chip to be ready again, and
>>>> checking the operation status). But in some cases, advanced controller
>>>> drivers might want to optimize this and craft their own page write
>>>> helper to leverage additional hardware capabilities, thus not always
>>>> using the core facilities.
>>>>
>>>> Some drivers, like this one, do not use the core helper to finish a page
>>>> write because the final cycles are automatically managed by the
>>>> hardware. In this case, the additional care must be taken to manually
>>>> perform the final status check.
>>>>
>>>> Let's read the NAND chip status at the end of the page write helper and
>>>> return -EIO upon error.
>>>>
>>>> Cc: Michal Simek <michal.simek@amd.com>
>>>> Cc: stable@vger.kernel.org
>>>> Fixes: 88ffef1b65cf ("mtd: rawnand: arasan: Support the hardware BCH ECC engine")
>>>> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
>>>>
>>>> ---
>>>>
>>>> Hello Michal,
>>>>
>>>> I have not tested this, but based on a report on another driver, I
>>>> believe the status check is also missing here and could sometimes
>>>> lead to unnoticed partial writes.
>>>>
>>>> Please test on your side that everything still works and let me
>>>> know how it goes.
>>>
>>> Any news from the testing team about patches 2/3 and 3/3?
>>
>> I asked Amit to test and he didn't get back to me even I asked for it couple of times.
>
> Ok.
>
>> Can you please tell me how to test it? I will setup HW myself and test it and get back to you.
>
> I believe setting up the board to use the hardware BCH engine and
> performing basic erase/write/read testing with a known file and check
> it still behaves correctly would work. You can also run
>
> nandbiterrs -i /dev/mtdx
>
> as a second step and verify there is no difference with and without the
> patch and finally check the impact:
>
> flash_speed -d -c 10 /dev/mtdx
> (be careful: this is a destructive operation)

I run this myself.

pl353 test log before the patch.

# cat /proc/mtd
dev: size erasesize name
mtd0: 10000000 00020000 "pl35x-nand-controller"
# nandbiterrs -i /dev/mtd0
incremental biterrors test
Successfully corrected 0 bit errors per subpage
Inserted biterror @ 0/5
Read reported 1 corrected bit errors
Successfully corrected 1 bit errors per subpage
Inserted biterror @ 0/2
Failed to recover 1 bitflips
Read error after 2 bit errors per page
# flash_speed -d -c 10 /dev/mtd0
scanning for bad eraseblocks
scanned 10 eraseblocks, 0 are bad
testing eraseblock write speed
eraseblock write speed is 4555 KiB/s
testing eraseblock read speed
eraseblock read speed is 5765 KiB/s
testing page write speed
page write speed is 4383 KiB/s
testing page read speed
page read speed is 5614 KiB/s
testing 2 page write speed
2 page write speed is 4444 KiB/s
testing 2 page read speed
2 page read speed is 5688 KiB/s
Testing erase speed
erase speed is 320000 KiB/s
Testing 2x multi-block erase speed
2x multi-block erase speed is 320000 KiB/s
Testing 4x multi-block erase speed
4x multi-block erase speed is 320000 KiB/s
Testing 8x multi-block erase speed
8x multi-block erase speed is 320000 KiB/s
Testing 16x multi-block erase speed
16x multi-block erase speed is 320000 KiB/s
Testing 32x multi-block erase speed
32x multi-block erase speed is 320000 KiB/s
Testing 64x multi-block erase speed
64x multi-block erase speed is 320000 KiB/s
finished
# dmesg | grep nand
[ 2.876719] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
[ 2.883130] nand: Micron MT29F2G08ABAEAWP
[ 2.887230] nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB
size: 64
#

When applied

# cat /proc/mtd
dev: size erasesize name
mtd0: 10000000 00020000 "pl35x-nand-controller"
# nandbiterrs -i /dev/mtd0
incremental biterrors test
Successfully corrected 0 bit errors per subpage
Inserted biterror @ 0/5
Read reported 1 corrected bit errors
Successfully corrected 1 bit errors per subpage
Inserted biterror @ 0/2
Failed to recover 1 bitflips
Read error after 2 bit errors per page
# flash_speed -d -c 10 /dev/mtd0
scanning for bad eraseblocks
scanned 10 eraseblocks, 0 are bad
testing eraseblock write speed
eraseblock write speed is 4522 KiB/s
testing eraseblock read speed
eraseblock read speed is 5765 KiB/s
testing page write speed
page write speed is 4383 KiB/s
testing page read speed
page read speed is 5638 KiB/s
testing 2 page write speed
2 page write speed is 4444 KiB/s
testing 2 page read speed
2 page read speed is 5714 KiB/s
Testing erase speed
erase speed is 320000 KiB/s
Testing 2x multi-block erase speed
2x multi-block erase speed is 320000 KiB/s
Testing 4x multi-block erase speed
4x multi-block erase speed is 320000 KiB/s
Testing 8x multi-block erase speed
8x multi-block erase speed is 320000 KiB/s
Testing 16x multi-block erase speed
16x multi-block erase speed is 320000 KiB/s
Testing 32x multi-block erase speed
32x multi-block erase speed is 320000 KiB/s
Testing 64x multi-block erase speed
64x multi-block erase speed is 320000 KiB/s
finished
# dmesg | grep nand
[ 2.896206] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
[ 2.902648] nand: Micron MT29F2G08ABAEAWP
[ 2.906667] nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB
size: 64

Behavior is the same. Speed is changing on every run.

I don't have zynqmp board here but will try to get data asap.

Thanks,
Michal