From mboxrd@z Thu Jan  1 00:00:00 1970
From: jlu@pengutronix.de (Jan =?ISO-8859-1?Q?L=FCbbe?=)
Date: Fri, 09 Jun 2017 10:58:12 +0200
Subject: [RFC PATCH 3/4] ARM: l2x0: add arm,ecc-enable property for aurora
In-Reply-To: <20170608041124.4624-4-chris.packham@alliedtelesis.co.nz>
References: <20170608041124.4624-1-chris.packham@alliedtelesis.co.nz>
 <20170608041124.4624-4-chris.packham@alliedtelesis.co.nz>
Message-ID: <1496998692.3536.24.camel@pengutronix.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Do, 2017-06-08 at 16:11 +1200, Chris Packham wrote:
> +       if (of_property_read_bool(np, "arm,ecc-enable")) {
> +               mask |= L2C_AUX_CTRL_EVTMON_ENABLE;
> +               val |= L2C_AUX_CTRL_EVTMON_ENABLE;
> +       } else if (of_property_read_bool(np, "arm,ecc-disable")) {
> +               mask |= L2C_AUX_CTRL_EVTMON_ENABLE;
> +       }

Unless I misunderstand the code in __l2c_init(), the mask is used to
specify the bits to preserve:
        old_aux = aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
        aux &= aux_mask;
        aux |= aux_val;

        if (old_aux != aux)
                pr_warn("L2C: DT/platform modifies aux control register: 0x%08x -> 0x%08x\n",
                        old_aux, aux);

So the arm,ecc-disable property will have no effect. This probably also
applies to patch 2/4. The existing property *-disable code removes the
corresponding bit from the mask.

Regards,
Jan
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