Date: Thu, 30 Jul 2015 18:13:21 +0200
From: Albert ARIBAUD <albert.aribaud@3adev.fr>
To: Stefan Agner <stefan@agner.ch>
Cc: dwmw2@infradead.org, computersforpeace@gmail.com, sebastian@breakpoint.cc,
        robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com,
        ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
        shawn.guo@linaro.org, kernel@pengutronix.de,
        boris.brezillon@free-electrons.com, marb@ixxat.de,
        aaron@tastycactus.com, bpringlemeir@gmail.com,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Bill Pringlemeir <bpringlemeir@nbsps.com>
Subject: Re: [PATCH v8 1/5] mtd: nand: vf610_nfc: Freescale NFC for VF610,
 MPC5125 and others
Message-ID: <20150730181321.3bd38db7.albert.aribaud@3adev.fr>
In-Reply-To: <1438015365-15685-2-git-send-email-stefan@agner.ch>
References: <1438015365-15685-1-git-send-email-stefan@agner.ch>
	<1438015365-15685-2-git-send-email-stefan@agner.ch>
Organization: 3ADEV
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1775
Lines: 56

Hi Stefan,

Le Mon, 27 Jul 2015 18:42:41 +0200, Stefan Agner <stefan@agner.ch> a
écrit :

> This driver supports Freescale NFC (NAND flash controller) found on
> Vybrid (VF610), MPC5125, MCF54418 and Kinetis K70. The driver has
> been tested on 8-bit and 16-bit NAND interface and supports ONFI
> parameter page reading.
> 
> [...]
> 
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> new file mode 100644
> index 0000000..0da500e
> --- /dev/null
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -0,0 +1,640 @@
> [...]

... about line 708:

> +	err = devm_request_irq(nfc->dev, irq, vf610_nfc_irq, 0, DRV_NAME, mtd);
> +	if (err) {
> +		dev_err(nfc->dev, "Error requesting IRQ!\n");
> +		goto error;
> +	}
> +
> +	vf610_nfc_init_controller(nfc);

The call above is too early: vf610_nfc_init_controller() will test
for (nfc->chip.options & NAND_BUSWIDTH_16) but this option bit is only
set once nand_scan_ident() below has been run.

This has the effect that even when the DT node specifies a 16-bit wide
bus, the controller is configured for 8-bit mode at this point, which of
course causes read failures. I've experienced this with a Vybrid SoC
and a Micron MT29F4G16ABADAH4 16-bit NAND.

> +	/* first scan to find the device and get the page size */
> +	if (nand_scan_ident(mtd, 1, NULL)) {
> +		err = -ENXIO;
> +		goto error;
> +	}

Placing the call to vf610_nfc_init_controller() here, after the call
to nand_scan_ident() rather than before it, fixed the issue for me.

Cordialement,
Albert ARIBAUD
3ADEV
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/