Re: [PATCH 07/13] arm64: dts: ti: k3-am69-aquila: fix USB clocking for compliance
From: Siddharth Vadapalli
Date: Tue May 05 2026 - 07:37:03 EST
On 05/05/26 16:38, Francesco Dolcini wrote:
Hi Siddharth,Thank you for pointing it out. I will fix this in all relevant patches of this series and post the v2 series in a day (to allow others to review as well).
On Tue, May 05, 2026 at 04:36:08PM +0530, Siddharth Vadapalli wrote:
According to section "6.5.3 Normative Spread Spectrum Clocking (SSC)" of
the USB 3.2 Specification, SSC should be enabled by default. This protects
against EMI violations. Hence, enable internal SSC for USB SuperSpeed.
Fixes: 39ac6623b1d8 ("arm64: dts: ti: Add Aquila AM69 Support")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
---
arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi b/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
index 5119baf62a4c..7c98ee81ccb5 100644
--- a/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
@@ -1423,6 +1423,7 @@ serdes0_usb0_ss_link: phy@3 {
resets = <&serdes_wiz0 4>;
cdns,num-lanes = <1>;
cdns,phy-type = <PHY_TYPE_USB3>;
+ cdns,ssc-mode = <2>; /* 2 for internal SSC */
};
};
@@ -1502,6 +1503,11 @@ &serdes_ln_ctrl {
&serdes_wiz0 {
status = "okay";
+ ti,core-clk-sel = <1>; /* Select internal reference clock */
+ ti,ssc-enable; /* Enable SSC */
+ ti,ssc-type = <1>; /* 1 for Downspread */
+ ti,ssc-frequency-hz = <33000>; /* 33 KHz */
+ ti,ssc-depth-per-mil = <5>; /* 0.5% depth */
These properties must go before status. Please see the coding guideline.
As indicated in the cover letter, I was able to test this series on all TI Boards (EVMs / SKs). It will help if you could test this series on Toradex boards.
Regards,
Siddharth.