Have fsl_elbc_nand controllers subpage write support?

Pali Rohár
2022-08-07T12:00:55Z

Hello Scott!

In past you disabled nand subpage write support for freescale eLBC and
IFC U-Boot nand drivers in following patch:
https://lore.kernel.org/u-boot/20121102234432.GA18129@buserror.net/

But in Linux kernel you disabled it only in freescale IFC nand driver:
https://lore.kernel.org/linux-mtd/20130410223437.GA26900@home.buserror.net/

letting kernel's freescale eLBC driver to have enabled subpage write
support.

I would like to ask, has freescale eLBC nand controller support for
subpage writes? Or not and it should be disabled also in kernel?

Or has somebody else these details?

The main issue is that U-Boot nand and UBI support for boards with eLBC
controllers is compatible with Linux kernel nand and UBI support because
these two drivers calculate UBI geometry differently. UBI header offset
is calculated from nand subpage size and nand subpage size obviously
depends on the fact if subpage write is supported or not.

I would like to fix this issue, but I do not know if wrong information
is in U-Boot driver or in Linux kernel driver.