Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\))
Subject: Re: [PATCH 10/32] ARM: dts: omap3-gta04: update gpmc NAND setup
From:   "H. Nikolaus Schaller" <hns@goldelico.com>
In-Reply-To: <20180725081058.GB7467@lenoch>
Date:   Wed, 25 Jul 2018 10:16:28 +0200
Cc:     Marek Belisko <marek@goldelico.com>,
        =?utf-8?Q?Beno=C3=AEt_Cousson?= <bcousson@baylibre.com>,
        Tony Lindgren <tony@atomide.com>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        linux-omap@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <1E7B727D-1AED-4B00-AD2C-CF9FC562E53D@goldelico.com>
References: <cover.1532501910.git.hns@goldelico.com> <effe8969751cde3a3cd7993aa66c839493af9dd1.1532501910.git.hns@goldelico.com> <20180725081058.GB7467@lenoch>
To:     Ladislav Michl <ladis@linux-mips.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi,

> Am 25.07.2018 um 10:10 schrieb Ladislav Michl <ladis@linux-mips.org>:
>=20
> On Wed, Jul 25, 2018 at 08:58:42AM +0200, H. Nikolaus Schaller wrote:
>> to better match omap3-beagle.dts (which was the basis
>> of designing the GTA04).
>>=20
>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>> ---
>> arch/arm/boot/dts/omap3-gta04.dtsi | 14 +++++++-------
>> 1 file changed, 7 insertions(+), 7 deletions(-)
>>=20
>> diff --git a/arch/arm/boot/dts/omap3-gta04.dtsi =
b/arch/arm/boot/dts/omap3-gta04.dtsi
>> index 03fe404cbf56..9568e0c4d4bf 100644
>> --- a/arch/arm/boot/dts/omap3-gta04.dtsi
>> +++ b/arch/arm/boot/dts/omap3-gta04.dtsi
>> @@ -616,27 +616,27 @@
>> 		interrupt-parent =3D <&gpmc>;
>> 		interrupts =3D <0 IRQ_TYPE_NONE>, /* fifoevent */
>> 			     <1 IRQ_TYPE_NONE>;	/* termcount */
>> +		ti,nand-ecc-opt =3D "ham1";
>> +		rb-gpios =3D <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 =
*/
>> 		nand-bus-width =3D <16>;
>> -		ti,nand-ecc-opt =3D "bch8";
>=20
> You are using weeker ECC scheme just to be compatible with another =
machine?

No not another machine. The GTA04 uses the same SoC and NAND chip as the =
BeagleBoard,
so you can imagine GTA04 being a BeagleBoard + a lot of other things.

The key reason is to change the ecc scheme is to be compatible with the =
U-Boot used.

BootROM can only handle ham1 for the MLO. And there is no nand-ecc-opt
for each partition. So we either can't mix ECC schemes if we want to be =
able
to read/write MLO as the first partition from kernel.

> So now you cannot boot already deployed filesystem...

No. We always used ham1 and bch8 wasn't working at all here. Therefore =
nobody
did use upstream kernel for NAND yet...

> Also is it enough for
> NAND chip used?

Well, the chip is recommended to use bch8 but BootROM imposes above =
mentioned limits.

BR,
Nikolaus

>=20
> 	ladis
>=20
>> +		#address-cells =3D <1>;
>> +		#size-cells =3D <1>;
>>=20
>> -		gpmc,sync-clk-ps =3D <0>;
>> +		gpmc,device-width =3D <2>;
>> 		gpmc,cs-on-ns =3D <0>;
>> 		gpmc,cs-rd-off-ns =3D <44>;
>> 		gpmc,cs-wr-off-ns =3D <44>;
>> 		gpmc,adv-on-ns =3D <6>;
>> 		gpmc,adv-rd-off-ns =3D <34>;
>> 		gpmc,adv-wr-off-ns =3D <44>;
>> -		gpmc,we-off-ns =3D <40>;
>> 		gpmc,oe-off-ns =3D <54>;
>> +		gpmc,we-off-ns =3D <40>;
>> 		gpmc,access-ns =3D <64>;
>> 		gpmc,rd-cycle-ns =3D <82>;
>> 		gpmc,wr-cycle-ns =3D <82>;
>> 		gpmc,wr-access-ns =3D <40>;
>> 		gpmc,wr-data-mux-bus-ns =3D <0>;
>> -		gpmc,device-width =3D <2>;
>> -
>> -		#address-cells =3D <1>;
>> -		#size-cells =3D <1>;
>> +		gpmc,sync-clk-ps =3D <0>;
>>=20
>> 		x-loader@0 {
>> 			label =3D "X-Loader";
>> --=20
>> 2.12.2
>>=20
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" =
in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html