From: Krzysztof Kozlowski <krzk@kernel.org>
To: Guillaume Tucker <guillaume.tucker@collabora.com>
Cc: Russell King <linux@armlinux.org.uk>,
Kukjin Kim <kgene@kernel.org>,
Kyungmin Park <kyungmin.park@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel@collabora.com
Subject: Re: [PATCH] ARM: exynos: clear L310_AUX_CTRL_FULL_LINE_ZERO in default l2c_aux_val
Date: Tue, 23 Jun 2020 08:12:18 +0200 [thread overview]
Message-ID: <20200623061218.GA2983@kozik-lap> (raw)
In-Reply-To: <c6d979c0050502cd1bca8619cb5ff95db239db12.1591969825.git.guillaume.tucker@collabora.com>
On Fri, Jun 12, 2020 at 02:58:37PM +0100, Guillaume Tucker wrote:
> This "alert" error message can be seen on exynos4412-odroidx2:
>
> L2C: platform modifies aux control register: 0x02070000 -> 0x3e470001
> L2C: platform provided aux values permit register corruption.
>
> Followed by this plain error message:
>
> L2C-310: enabling full line of zeros but not enabled in Cortex-A9
>
> To fix it, don't set the L310_AUX_CTRL_FULL_LINE_ZERO flag (bit 0) in
> the default value of l2c_aux_val. It may instead be enabled when
> applicable by the logic in l2c310_enable() if the attribute
> "arm,full-line-zero-disable" was set in the device tree.
>
> The initial commit that introduced this default value was in v2.6.38:
>
> 1cf0eb799759 "ARM: S5PV310: Add L2 cache init function in cpu.c"
Run checkpatch in the future on your patches.
I fixed it up.
Best regards,
Krzysztof
>
> However, the code to set the L310_AUX_CTRL_FULL_LINE_ZERO flag and
> manage that feature was added much later and the default value was not
> updated then. So this seems to have been a subtle oversight
> especially since enabling it only in the cache and not in the A9 core
> doesn't actually prevent the platform from running. According to the
> TRM, the opposite would be a real issue, if the feature was enabled in
> the A9 core but not in the cache controller.
>
> Reported-by: "kernelci.org bot" <bot@kernelci.org>
> Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
> ---
> arch/arm/mach-exynos/exynos.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
> index 7a8d1555db40..36c37444485a 100644
> --- a/arch/arm/mach-exynos/exynos.c
> +++ b/arch/arm/mach-exynos/exynos.c
> @@ -193,7 +193,7 @@ static void __init exynos_dt_fixup(void)
> }
>
> DT_MACHINE_START(EXYNOS_DT, "Samsung Exynos (Flattened Device Tree)")
> - .l2c_aux_val = 0x3c400001,
> + .l2c_aux_val = 0x3c400000,
> .l2c_aux_mask = 0xc20fffff,
> .smp = smp_ops(exynos_smp_ops),
> .map_io = exynos_init_io,
> --
> 2.20.1
>
prev parent reply other threads:[~2020-06-23 6:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-12 13:58 [PATCH] ARM: exynos: clear L310_AUX_CTRL_FULL_LINE_ZERO in default l2c_aux_val Guillaume Tucker
2020-06-22 17:50 ` Krzysztof Kozlowski
2020-06-23 6:12 ` Krzysztof Kozlowski [this message]
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