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

From: Dinh Nguyen
Date: Tue Sep 10 2019 - 11:22:38 EST

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:
>> 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.