On Wed, Mar 10, 2021 at 10:54:05AM +0800, dillon min wrote: > Hi Sascha, > > Thanks for reviewing. > > On Tue, Mar 9, 2021 at 8:18 PM Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > > > On Tue, Mar 09, 2021 at 02:15:19PM +0800, dillon.minfei@xxxxxxxxx wrote: > > > From: dillon min <dillon.minfei@xxxxxxxxx> > > > > > > This patch intend to fix ubi filesystem mount failed on MYS-6ULX-IOT board, > > > from Micron MT29F2G08ABAEAWP's datasheets, we need to choose 4-bit ECC. > > > > > > Table 18: Error Management Details > > > > > > Description Requirement > > > > > > Minimum number of valid blocks (NVB) per LUN 2008 > > > Total available blocks per LUN 2048 > > > First spare area location x8: byte 2048 x16: word 1024 > > > Bad-block mark x8: 00h x16: 0000h > > > Minimum required ECC 4-bit ECC per 528 bytes > > > Minimum ECC with internal ECC enabled 4-bit ECC per 516 bytes (user data) + 8 > > > bytes (parity data) > > > Minimum required ECC for block 0 if PROGRAM/ > > > ERASE cycles are less than 1000 1-bit ECC per 528 bytes > > > > 4-bit ECC is the minimum this chip requires. There's nothing wrong with > > choosing a better ECC like the GPMI driver does by default. > > > Yes, indeed, the mt29f2g08's minimum ecc is 4-bit, you can use 8-bits ecc. > but there is a dependency between new kernel gpmi-nand with the old > mfg-kernel's , which means > if the old nand ecc layout is 4-bits, you should use ecc 4-bit in the > new kernel (by fsl,use-minimum-ecc), > else use 8-bits. > > For my case, the ubifs filesystem was created by ecc 4-bits, without > reflash filesystem or change Then this is the justification for this patch, not anything from the datasheet like you've written in your commit message. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
