Re: mtd raw nand denali.c broken for Intel/Altera Cyclone V

[Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>]

Hi Dinh,

On Wed, Sep 11, 2019 at 12:22 AM Dinh Nguyen <dinguyen@xxxxxxxxxx> wrote:
>
>
>
> On 9/10/19 8:48 AM, Tim Sander wrote:
> > Hi
> >
> > I have noticed that my SPF records where not in place after moving the server,
> > so it seems the mail didn't go to the mailing list. Hopefully that's fixed now.
> >
> > Am Dienstag, 10. September 2019, 09:16:37 CEST schrieb Masahiro Yamada:
> >> On Fri, Sep 6, 2019 at 9:39 PM Tim Sander <tim@xxxxxxxxxxxxxxx> wrote:
> >>> Hi
> >>>
> >>> I have noticed that there multiple breakages piling up for the denali nand
> >>> driver on the Intel/Altera Cyclone V. Unfortunately i had no time to track
> >>> the mainline kernel closely. So the breakage seems to pile up. I am a
> >>> little disapointed that Intel is not on the lookout that the kernel works
> >>> on the chips they are selling. I was really happy about the state of the
> >>> platform before concerning mainline support.
> >>>
> >>> The failure starts with kernel 4.19 or stable kernel release 4.18.19. The
> >>> commit is ba4a1b62a2d742df9e9c607ac53b3bf33496508f.
> >>
> >> Just for clarification, this corresponds to
> >> 0d55c668b218a1db68b5044bce4de74e1bd0f0c8 upstream.
> >>
> >>> The problem here is that
> >>> our platform works with a zero in the SPARE_AREA_SKIP_BYTES register.
> >>
> >> Please clarify the scope of "our platform".
> >> (Only you, or your company, or every individual using this chip?)
> > The company i work for uses this chip as a base for multiple products.
> >
> >> First, SPARE_AREA_SKIP_BYTES is not the property of the hardware.
> >> Rather, it is about the OOB layout, in other words, this parameter
> >> is defined by software.
> >>
> >> For example, U-Boot supports the Denali NAND driver.
> >> The SPARE_AREA_SKIP_BYTES is a user-configurable parameter:
> >> https://github.com/u-boot/u-boot/blob/v2019.10-rc3/drivers/mtd/nand/raw/Kcon
> >> fig#L112
> >>
> >>
> >> Your platform works with a zero in the SPARE_AREA_SKIP_BYTES register
> >> because the NAND chip on the board was initialized with a zero
> >> set to the SPARE_AREA_SKIP_BYTES register.
> >>
> >> If the NAND chip had been initialized with 8
> >> set to the SPARE_AREA_SKIP_BYTES register, it would have
> >> been working with 8 to the SPARE_AREA_SKIP_BYTES.
> >>
> >> The Boot ROM is the only (semi-)software that is unconfigurable by users,
> >> so the value of SPARE_AREA_SKIP_BYTES should be aligned with
> >> the boot ROM.
> >> I recommend you to check the spec of the boot ROM.
> > We boot from NOR flash. That's why i didn't see a problem booting probably.
> >
> >> (The maintainer of the platform, Dihn is CC'ed,
> >> so I hope he will jump in)
> > Yes i hope so too.
> >
>
> I don't have access to a NAND device at the moment. I'll try to find one
> and debug.
>
> Dinh


Dinh,
Do you have answers for the following questions?


- Does the SOCFPGA boot ROM support the NAND boot mode?

- If so, which value does it use for SPARE_AREA_SKIP_BYTES?




-- 
Best Regards
Masahiro Yamada

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