Re: [PATCH 3/3] arm64: dts: rockchip: Add HDMI PHY PLL clock source to VOP2 on rk3576

From: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
To: Piotr Oniszczuk <piotr.oniszczuk@gmail.com>
Cc: "Sandy Huang" <hjc@rock-chips.com>,
	"Heiko Stübner" <heiko@sntech.de>,
	"Andy Yan" <andy.yan@rock-chips.com>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Simona Vetter" <simona@ffwll.ch>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	kernel@collabora.com, "Andy Yan" <andyshrk@163.com>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski@linaro.org>,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH 3/3] arm64: dts: rockchip: Add HDMI PHY PLL clock source to VOP2 on rk3576
Date: Thu, 12 Jun 2025 14:04:09 +0300	[thread overview]
Message-ID: <535a4e1c-33d3-4941-8315-df20d4dec799@collabora.com> (raw)
In-Reply-To: <01D5D2D8-392B-4926-884E-1A4FB87C03CF@gmail.com>

On 6/12/25 1:22 PM, Piotr Oniszczuk wrote:
> 
> 
>> Wiadomość napisana przez Cristian Ciocaltea <cristian.ciocaltea@collabora.com> w dniu 11 cze 2025, o godz. 23:47:
>>
>> Since commit c871a311edf0 ("phy: rockchip: samsung-hdptx: Setup TMDS
>> char rate via phy_configure_opts_hdmi"), the workaround of passing the
>> rate from DW HDMI QP bridge driver via phy_set_bus_width() became
>> partially broken, as it cannot reliably handle mode switches anymore.
>>
>> Attempting to fix this up at PHY level would not only introduce
>> additional hacks, but it would also fail to adequately resolve the
>> display issues that are a consequence of the system CRU limitations.
>>
>> Instead, proceed with the solution already implemented for RK3588: make
>> use of the HDMI PHY PLL as a better suited DCLK source for VOP2. This
>> will not only address the aforementioned problem, but it should also
>> facilitate the proper operation of display modes up to 4K@60Hz.
>>
>> It's worth noting that anything above 4K@30Hz still requires high TMDS
>> clock ratio and scrambling support, which hasn't been mainlined yet.
>>
>> Fixes: d74b842cab08 ("arm64: dts: rockchip: Add vop for rk3576")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
>> arch/arm64/boot/dts/rockchip/rk3576.dtsi | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk3576.dtsi b/arch/arm64/boot/dts/rockchip/rk3576.dtsi
>> index 6a13fe0c3513fb2ff7cd535aa70e3386c37696e4..b1ac23035dd789f0478bf10c78c74ef167d94904 100644
>> --- a/arch/arm64/boot/dts/rockchip/rk3576.dtsi
>> +++ b/arch/arm64/boot/dts/rockchip/rk3576.dtsi
>> @@ -1155,12 +1155,14 @@ vop: vop@27d00000 {
>> <&cru HCLK_VOP>,
>> <&cru DCLK_VP0>,
>> <&cru DCLK_VP1>,
>> - <&cru DCLK_VP2>;
>> + <&cru DCLK_VP2>,
>> + <&hdptxphy>;
>> clock-names = "aclk",
>>      "hclk",
>>      "dclk_vp0",
>>      "dclk_vp1",
>> -      "dclk_vp2";
>> +      "dclk_vp2",
>> +      "pll_hdmiphy0";
>> iommus = <&vop_mmu>;
>> power-domains = <&power RK3576_PD_VOP>;
>> rockchip,grf = <&sys_grf>;
>>
>> -- 
>> 2.49.0
>>
>>
>> _______________________________________________
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>> Linux-rockchip@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-rockchip
> 
> Cristian,
> It fixes fractional hd modes for me on rk3576.
> Thx for this fix!

Thanks for testing! :)