Subject: Re: [RFT PATCH] ARM: dts: exynos: Enable Mixer node for Exynos5800
 Peach Pi machine
To: Javier Martinez Canillas <javierm@redhat.com>,
        linux-kernel@vger.kernel.org
Cc: Guillaume Tucker <guillaume.tucker@collabora.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Shuah Khan <shuahkh@osg.samsung.com>, devicetree@vger.kernel.org,
        Kukjin Kim <kgene@kernel.org>, Russell King <linux@armlinux.org.uk>,
        linux-samsung-soc@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-arm-kernel@lists.infradead.org
From: Marek Szyprowski <m.szyprowski@samsung.com>
Message-id: <3e6e4b15-9f8a-bea1-3c8e-2d85fc4c512d@samsung.com>
Date: Tue, 12 Dec 2017 08:01:27 +0100
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Hi

On 2017-12-11 23:48, Javier Martinez Canillas wrote:
> Commit 1cb686c08d12 ("ARM: dts: exynos: Add status property to Exynos 542x
> Mixer nodes") disabled the Mixer node by default in the DTSI and enabled
> for each Exynos 542x DTS. But unfortunately it missed to enable it for the
> Exynos5800 Peach Pi machine, since the 5800 is also an 542x SoC variant.
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

> ---
>
> I believe this may cause the boot issues reported on Exynos5800 Peach Pi
> from v4.15-rc3, the mentioned commit made to v4.15-rc1 but it seems that
> didn't cause any harm until commit ("510353a63796 drm/bridge: analogix
> dp: Fix runtime PM state in get_modes() callback") fixed the runtime PM
> management in the DP driver.

Thanks for analyzing this. Lack of this change was probably responsible for
Exynos DRM initialization failure ("exynos-drm exynos-drm: failed to bind
14530000.hdmi (ops hdmi_component_ops): -1" message and probably further
error "unbalanced disables for lcd_vdd", which shows that failure path of
analogix dp and simple panel causes unbalanced regulator disable.

This patch should go to v4.15-rcX (fixes) if possible.

> I can't test right now, but I'm posting anyways as a RFT in case others
> that have access to a Peach Pi can test it.
>
> Best regards,
> Javier
>
>   arch/arm/boot/dts/exynos5800-peach-pi.dts | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm/boot/dts/exynos5800-peach-pi.dts b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> index b2b95ff205e8..0029ec27819c 100644
> --- a/arch/arm/boot/dts/exynos5800-peach-pi.dts
> +++ b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> @@ -664,6 +664,10 @@
>   	status = "okay";
>   };
>   
> +&mixer {
> +	status = "okay";
> +};
> +
>   /* eMMC flash */
>   &mmc_0 {
>   	status = "okay";

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland