[PATCH] mtd: rawnand: fsl_elbc: Remove NAND_NO_SUBPAGE_WRITE flag

[Pali Rohár]

On Monday 15 August 2022 23:49:17 Michael Nazzareno Trimarchi wrote:
> Hi
> 
> Il lun 15 ago 2022, 10:01 Pali Rohár <pali at kernel.org> ha scritto:
> 
> > Subpage write support for freescale eLBC NAND controller driver is
> > implemented in U-Boot and was fixes in the commit d3963721d93f ("nand: Sync
> > with Linux v4.1").
> >
> > So remove NAND_NO_SUBPAGE_WRITE flag from the fsl_elbc_nand.c driver. This
> > partially revert commit cb04c7723429 ("nand/fsl: add NAND_NO_SUBPAGE_WRITE
> > to eLBC and IFC drivers"), only eLBC driver part.
> >
> > With this change U-Boot with default settings can read from NAND UBIFS
> > image created on Linux with Linux default settings. Prior this change
> > U-Boot was unable to read from NAND UBIFS images created with Linux default
> > settings due to differnet UBI geometry.
> >
> > Linux kernel fsl_elbc_nand.c driver also does not set NAND_NO_SUBPAGE_WRITE
> > flag and has implemented subpage write support.
> >
> > Fixes: cb04c7723429 ("nand/fsl: add NAND_NO_SUBPAGE_WRITE to eLBC and IFC
> > drivers")
> > Fixes: d3963721d93f ("nand: Sync with Linux v4.1")
> > Signed-off-by: Pali Rohár <pali at kernel.org>
> > ---
> > See also email thread:
> > https://lore.kernel.org/u-boot/20220807120027.2zz43afbqtqljhul@pali/t/#u
> > ---
> >  drivers/mtd/nand/raw/fsl_elbc_nand.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/mtd/nand/raw/fsl_elbc_nand.c
> > b/drivers/mtd/nand/raw/fsl_elbc_nand.c
> > index 48a3687f2728..e28670a4724a 100644
> > --- a/drivers/mtd/nand/raw/fsl_elbc_nand.c
> > +++ b/drivers/mtd/nand/raw/fsl_elbc_nand.c
> > @@ -732,7 +732,6 @@ static int fsl_elbc_chip_init(int devnum, u8 *addr,
> > struct udevice *dev)
> >         nand->bbt_md = &bbt_mirror_descr;
> >
> >         /* set up nand options */
> > -       nand->options = NAND_NO_SUBPAGE_WRITE;
> >         nand->bbt_options = NAND_BBT_USE_FLASH;
> >
> >         nand->controller = &elbc_ctrl->controller;
> >
> 
> Reviewed-by: Michael Trimarchi <michael at amarulasolutions.com>
> 
> I was following the thread. Please confirm that you was able to test

Yes, I have tested this change on P2020 based board Turris 1.1. And
finally U-Boot by default was able to access UBI created by mainline
Linux with default parameters, just by calling 'ubi part rootfs'.
UBI created by sub-page of size 2048 can be still also read by U-Boot by
calling 'ubi part rootfs 2048'. For this purpose I already provided
distroboot patch to easily specify UBI header offset (which is by
default sub-page size):
https://lore.kernel.org/u-boot/20220807190422.20157-1-pali@kernel.org/

> Michael
> 
> > --
> > 2.20.1
> >
> >