GPMI NAND Regression on i.MX6S

[Frieder Schrempf]

Hi Tim,

Am 16.03.22 um 17:34 schrieb Tim Harvey:
> On Wed, Mar 16, 2022 at 7:09 AM Fabio Estevam <festevam at gmail.com> wrote:
>>
>> Adding Han Xu's NXP email on Cc.
>>
>> On Mon, Mar 14, 2022 at 10:31 AM Frieder Schrempf
>> <frieder.schrempf at kontron.de> wrote:
>>>
>>> Hello everyone,
>>>
>>> sorry to dig out an old thread, but the below patch which was applied
>>> upstream as 616f03dabacb causes a regression for me when trying to
>>> attach an UBI volume with U-Boot 2022.01 on a board with i.MX6 Solo and
>>> AMD/Spansion parallel NAND.
>>>
>>> The failure looks like this:
>>>
>>> ubi0: attaching mtd2
>>> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes
>>> from PEB 0:0, read 64 bytes
>>> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 2048 bytes
>>> from PEB 0:2048, read 2048 bytes
>>> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes
>>> from PEB 1:0, read 64 bytes
>>> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 2048 bytes
>>> from PEB 1:2048, read 2048 bytes
>>>
>>> The NAND as reported by Linux is:
>>>
>>> nand: device found, Manufacturer ID: 0x01, Chip ID: 0xdc
>>> nand: AMD/Spansion S34ML04G1
>>> nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
>>>
>>> A different revision of the same board with a different NAND from
>>> manufacturer ESMT doesn't show the issue:
>>>
>>> nand: device found, Manufacturer ID: 0xc8, Chip ID: 0xdc
>>> nand: ESMT NAND 512MiB 3,3V 8-bit
>>> nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
>>>
>>> When I revert the mentioned commit (see patch here: [1]), the UBI boot
>>> starts working again.
>>>
>>> Does anyone know what the problem is and how to properly solve it?
>>>
>>> Thanks for any help!
>>> Frieder
>>>
>>> [1]
>>> https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fzerobin.net%2F%3F57a57a322bbdcf3c%23rZa3vHlWi%2BRxtRomoljtrngqWwiv6v4Js%2F2LNfdV10o%3D&data=04%7C01%7Cfrieder.schrempf%40kontron.de%7C978979eaf1fa48171bab08da076aea84%7C8c9d3c973fd941c8a2b1646f3942daf1%7C0%7C0%7C637830453031595997%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=NGl%2FrFnffV2oC90js0aHyTvoZjnrzW%2FD830lOnR4TbQ%3D&reserved=0
>>>
> 
> Frieder,
> 
> I see the same issue here with IMX6Q/DL GPMI NAND.
> 
> If I re-flash the ubi within U-Boot (tftpboot $loadaddr rootfs.ubi &&
> nand erase.part rootfs && nand write $loadaddr rootfs $filesize) I
> find that U-Boot can attach and mount the ubi fine but Linux will have
> issues

Interesting! This sounds like U-Boot and Linux somehow diverge in how
they handle the ECC data in OOB. I'm pretty confident that Linux does
things "correctly" and U-Boot should match what Linux does in this case.

Does the patch (revert of 616f03dabacb) I mentioned before "solve" the
issue for your case, too?

@Han, Ye, Peng: As you signed-off the mentioned commit, do you have any
ideas for a fix?

Thanks
Frieder