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

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On 9/12/23 16:17, Miquel Raynal wrote:
Hi Michal,

michal.simek@xxxxxxx 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@xxxxxxxxxxx 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*

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@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 88ffef1b65cf ("mtd: rawnand: arasan: Support the hardware BCH ECC engine")
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>


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.


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)

Testing team won't see any issue that's why feel free to add my
Acked-by: Michal Smek <michal.simek@xxxxxxx>


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