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

From: Dinh Nguyen <dinguyen@kernel.org>
To: Tim Sander <tim@krieglstein.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
	Richard Weinberger <richard@nod.at>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: mtd raw nand denali.c broken for Intel/Altera Cyclone V
Date: Tue, 10 Sep 2019 10:22:32 -0500	[thread overview]
Message-ID: <9bb2fb0e-a9e7-c389-f9b7-42367485ff83@kernel.org> (raw)
In-Reply-To: <3020870.hsMMj5ogRZ@dabox>

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@krieglstein.org> 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

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/