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From: Paul Cercueil <paul@crapouillou.net>
To: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Harvey Hunt <harveyhuntnexus@gmail.com>,
	list@opendingux.net, linux-mtd@lists.infradead.org,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-mips <linux-mips@vger.kernel.org>,
	Riccardo Mottola <riccardo.mottola@libero.it>,
	Discussions about the Letux Kernel 
	<letux-kernel@openphoenux.org>, Paul Boddie <paul@boddie.org.uk>
Subject: Re: [PATCH 0/3] mtd: Ingenic NAND fix for JZ4740
Date: Sun, 07 Nov 2021 18:43:33 +0000	[thread overview]
Message-ID: <LCT72R.SB2TF0MK7Q3B@crapouillou.net> (raw)
In-Reply-To: <968356A9-2A88-48B1-B31F-55C22BCE620E@goldelico.com>

Hi Nikolaus,

Le dim., nov. 7 2021 at 14:47:43 +0100, H. Nikolaus Schaller 
<hns@goldelico.com> a écrit :
> Hi Paul,
> 
>>  Am 09.10.2021 um 20:49 schrieb Paul Cercueil <paul@crapouillou.net>:
>> 
>>  Hi,
>> 
>>  Looks like NAND support has been broken on the JZ4740 SoC for a 
>> while;
> 
> Yes, I remember someone telling that something was fundamentally 
> broken
> and impossible to be fixed a while ago.

You mean MLC NAND, and that's still broken.

>>  it looks like it comes from the fact that the "hw_oob_first" 
>> mechanism
>>  was dropped from the NAND core and moved to the Davinci driver.
>> 
>>  It turns out the JZ4740 SoC needs it too; I didn't notice it when
>>  writing the new ingenic-nand driver (to replace the old jz4740-nand
>>  driver) most likely because my Device Tree had the "nand-ecc-mode" 
>> set
>>  to "hw_oob_first".
>> 
>>  I am not very sure about patch [1/3]; to me the original code does 
>> not
>>  make sense, and it didn't work out-of-the-box on the JZ4740 without 
>> it.
>>  By applying patch [1/3] the function 
>> nand_read_page_hwecc_oob_first()
>>  can be reused for the JZ4740 SoC as well. But I did not test patch 
>> [1/3]
>>  on Davinci.
> 
> would this also work for jz4780 NAND?

The JZ4780 NAND driver does work, but UBI refuses to use the CI20's 
NAND as it's a MLC.

-Paul



WARNING: multiple messages have this Message-ID (diff)
From: Paul Cercueil <paul@crapouillou.net>
To: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Harvey Hunt <harveyhuntnexus@gmail.com>,
	list@opendingux.net, linux-mtd@lists.infradead.org,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-mips <linux-mips@vger.kernel.org>,
	Riccardo Mottola <riccardo.mottola@libero.it>,
	Discussions about the Letux Kernel <letux-kernel@openphoenux.org>,
	Paul Boddie <paul@boddie.org.uk>
Subject: Re: [PATCH 0/3] mtd: Ingenic NAND fix for JZ4740
Date: Sun, 07 Nov 2021 18:43:33 +0000	[thread overview]
Message-ID: <LCT72R.SB2TF0MK7Q3B@crapouillou.net> (raw)
In-Reply-To: <968356A9-2A88-48B1-B31F-55C22BCE620E@goldelico.com>

Hi Nikolaus,

Le dim., nov. 7 2021 at 14:47:43 +0100, H. Nikolaus Schaller 
<hns@goldelico.com> a écrit :
> Hi Paul,
> 
>>  Am 09.10.2021 um 20:49 schrieb Paul Cercueil <paul@crapouillou.net>:
>> 
>>  Hi,
>> 
>>  Looks like NAND support has been broken on the JZ4740 SoC for a 
>> while;
> 
> Yes, I remember someone telling that something was fundamentally 
> broken
> and impossible to be fixed a while ago.

You mean MLC NAND, and that's still broken.

>>  it looks like it comes from the fact that the "hw_oob_first" 
>> mechanism
>>  was dropped from the NAND core and moved to the Davinci driver.
>> 
>>  It turns out the JZ4740 SoC needs it too; I didn't notice it when
>>  writing the new ingenic-nand driver (to replace the old jz4740-nand
>>  driver) most likely because my Device Tree had the "nand-ecc-mode" 
>> set
>>  to "hw_oob_first".
>> 
>>  I am not very sure about patch [1/3]; to me the original code does 
>> not
>>  make sense, and it didn't work out-of-the-box on the JZ4740 without 
>> it.
>>  By applying patch [1/3] the function 
>> nand_read_page_hwecc_oob_first()
>>  can be reused for the JZ4740 SoC as well. But I did not test patch 
>> [1/3]
>>  on Davinci.
> 
> would this also work for jz4780 NAND?

The JZ4780 NAND driver does work, but UBI refuses to use the CI20's 
NAND as it's a MLC.

-Paul



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  reply	other threads:[~2021-11-07 18:43 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-09 18:49 [PATCH 0/3] mtd: Ingenic NAND fix for JZ4740 Paul Cercueil
2021-10-09 18:49 ` Paul Cercueil
2021-10-09 18:49 ` [PATCH 1/3] mtd: rawnand/davinci: Don't calculate ECC when reading page Paul Cercueil
2021-10-09 18:49   ` Paul Cercueil
2021-10-09 18:49 ` [PATCH 2/3] mtd: rawnand: Export nand_read_page_hwecc_oob_first() Paul Cercueil
2021-10-09 18:49   ` Paul Cercueil
2021-10-15  6:13   ` Miquel Raynal
2021-10-15  6:13     ` Miquel Raynal
2021-10-15  8:38     ` Paul Cercueil
2021-10-15  8:38       ` Paul Cercueil
2021-10-15  8:51       ` Miquel Raynal
2021-10-15  8:51         ` Miquel Raynal
2021-10-15  9:27         ` Paul Cercueil
2021-10-15  9:27           ` Paul Cercueil
2021-10-15  9:35           ` Miquel Raynal
2021-10-15  9:35             ` Miquel Raynal
2021-10-15  9:38             ` Paul Cercueil
2021-10-15  9:38               ` Paul Cercueil
2021-10-15  9:44               ` Miquel Raynal
2021-10-15  9:44                 ` Miquel Raynal
2021-10-09 18:49 ` [PATCH 3/3] mtd: rawnand/ingenic: JZ4740 needs 'oob_first' read page function Paul Cercueil
2021-10-09 18:49   ` Paul Cercueil
2021-10-15  6:14   ` Miquel Raynal
2021-10-15  6:14     ` Miquel Raynal
2021-11-07 13:47 ` [PATCH 0/3] mtd: Ingenic NAND fix for JZ4740 H. Nikolaus Schaller
2021-11-07 13:47   ` H. Nikolaus Schaller
2021-11-07 18:43   ` Paul Cercueil [this message]
2021-11-07 18:43     ` Paul Cercueil

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