[EXT] Re: GPMI NAND Regression on i.MX6S

[Ye Li]

Hi Frieder,

On Thu, 2022-03-17 at 09:06 +0100, Frieder Schrempf wrote:
> Caution: EXT Email
> 
> 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F
> > > > %2Fzerobin.net%2F%3F57a57a322bbdcf3c%23rZa3vHlWi%2BRxtRomoljtrn
> > > > gqWwiv6v4Js%2F2LNfdV10o%3D&data=04%7C01%7Cye.li%40nxp.com%7
> > > > Cee3b85ceee3d4ece78e108da07ed1e2c%7C686ea1d3bc2b4c6fa92cd99c5c3
> > > > 01635%7C0%7C0%7C637831012279864791%7CUnknown%7CTWFpbGZsb3d8eyJW
> > > > IjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%
> > > > 7C3000&sdata=O6MzwCv9ClB8ZW7i3%2BV1RmOaviGqQRNa8L0uxE4M%2F%
> > > > 2BI%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?

The dt nand driver will check "fsl,legacy-bch-geometry" property to use
legacy bch. If this can't work for you in case you don't use DM driver,
I prefer adding a config to select the legacy bch not reverting the
patch. 

Best regards,
Ye Li
> 
> Thanks
> Frieder