[U-Boot] [linux-sunxi] Re: [RFC 02/11] mtd/nand: add ONFI timing mode to nand_timings converter

[Michal Suchanek]

On 8 June 2015 at 10:11, Roy Spliet <r.spliet at ultimaker.com> wrote:
> Hello Scott et al.,
>
> Op 06-06-15 om 00:02 schreef Scott Wood:
>
> On Fri, 2015-06-05 at 13:52 +0200, Roy Spliet wrote:
>
> From: yassin <yassinjaffer at gmail.com>
>
> Signed-off-by: Roy Spliet <r.spliet at ultimaker.com>
> ---
>  drivers/mtd/nand/Makefile       |   2 +-
>  drivers/mtd/nand/nand_timings.c | 252
> ++++++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/nand.h        |   3 +
>  3 files changed, 256 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/mtd/nand/nand_timings.c
>
> This code comes from Linux and yet I see no acknowledgement of that,
> much less a statement of which version of Linux this was pulled from.
>
> Correct, my apologies as I should have clarified that "work by Boris
> Brezillon" does not
> mean "upsteam work". The code comes from Boris' github tree[1] and contains
> work
> that was not yet brought upstream, yet is required for NAND on sunxi to
> work.
>
> It would probably be better to handle this as part of a general sync
> with the Linux mtd code.
>
> Ideally yes, but. In upstream Linux MTD we have a few issues to address as
> shown
> by Boris' patch-set, most importantly:
> - NAND chip timings (patch 1 to 3)
> - Randomisation support (patch 6)
> - Per-partition settings for ECC and randomisation (left out of my RFC,
> highly desirable
> but not strictly required for U-boot booting)

Hello,

as I understand it the ECC and randomisation settings for the
bootloader part of the nand are suboptimal or unusable for ubifs so if
u-boot SPL is to read the u-boot binary and later u-boot the kernel
from an ubifs volume it has to support non-uniform settings.
Alternatively the bootloader part can be extended to contain
partitions for u-boot binary and kernel image written to raw partition
without filesystem much like what Andriod usually does.

Thanks

Michal