Re: [PATCH] arm64: dts: rockchip: Assign RK3399 VDU clock rate
From: Nicolas Dufresne
Date: Tue Jun 07 2022 - 20:38:27 EST
Le mardi 07 juin 2022 à 14:15 -0700, Brian Norris a écrit :
> Before commit 9998943f6dfc ("media: rkvdec: Stop overclocking the
> decoder"), the rkvdec driver was forcing the VDU clock rate. After that
> commit, we rely on the default clock rate. That rate works OK on many
> boards, with the default PLL settings (CPLL is 800MHz, VDU dividers
> leave it at 400MHz); but some boards change PLL settings.
>
> Assign the expected default clock rate explicitly, so that the rate is
> consistent, regardless of PLL configuration.
>
> This was particularly broken on RK3399 Gru Scarlet systems, where the
> rk3399-gru-scarlet.dtsi assigns PLL_CPLL to 1.6 GHz, and so the VDU
> clock ends up at 800 MHz (twice the expected rate), and causes video
> artifacts and other issues.
>
> Note: I assign the clock rate in the clock controller instead of the
> vdec node, because there are multiple nodes that use this clock, and per
> the clock.yaml specification:
>
> Configuring a clock's parent and rate through the device node that
> consumes the clock can be done only for clocks that have a single
> user. Specifying conflicting parent or rate configuration in multiple
> consumer nodes for a shared clock is forbidden.
>
> Configuration of common clocks, which affect multiple consumer devices
> can be similarly specified in the clock provider node.
>
> Fixes: 9998943f6dfc ("media: rkvdec: Stop overclocking the decoder")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
My only doubt was if you really needed to duplicate that setting into gru-
scarlet.dtsi, but I've simply assumed the answer is yes, and that you already
checked that.
> ---
> This is a candidate for 5.19 IMO, since commit 9998943f6dfc landed in
> 5.19-rc1 and is being queued up for -stable as we speak.
>
> arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi | 4 +++-
> arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++--
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
> index 913d845eb51a..1977103a5ef4 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
> @@ -376,7 +376,8 @@ &cru {
> <&cru ACLK_VIO>,
> <&cru ACLK_GIC_PRE>,
> <&cru PCLK_DDR>,
> - <&cru ACLK_HDCP>;
> + <&cru ACLK_HDCP>,
> + <&cru ACLK_VDU>;
> assigned-clock-rates =
> <600000000>, <1600000000>,
> <1000000000>,
> @@ -388,6 +389,7 @@ &cru {
> <400000000>,
> <200000000>,
> <200000000>,
> + <400000000>,
> <400000000>;
> };
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> index fbd0346624e6..9d5b0e8c9cca 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> @@ -1462,7 +1462,8 @@ cru: clock-controller@ff760000 {
> <&cru HCLK_PERILP1>, <&cru PCLK_PERILP1>,
> <&cru ACLK_VIO>, <&cru ACLK_HDCP>,
> <&cru ACLK_GIC_PRE>,
> - <&cru PCLK_DDR>;
> + <&cru PCLK_DDR>,
> + <&cru ACLK_VDU>;
> assigned-clock-rates =
> <594000000>, <800000000>,
> <1000000000>,
> @@ -1473,7 +1474,8 @@ cru: clock-controller@ff760000 {
> <100000000>, <50000000>,
> <400000000>, <400000000>,
> <200000000>,
> - <200000000>;
> + <200000000>,
> + <400000000>;
> };
>
> grf: syscon@ff770000 {