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Subject: Re: [PATCH 0/3] mtd: Ingenic NAND fix for JZ4740
From:   "H. Nikolaus Schaller" <hns@goldelico.com>
In-Reply-To: <20211009184952.24591-1-paul@crapouillou.net>
Date:   Sun, 7 Nov 2021 14:47:43 +0100
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>
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References: <20211009184952.24591-1-paul@crapouillou.net>
To:     Paul Cercueil <paul@crapouillou.net>
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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.

> 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?

BR,
Nikolaus