Am 28.10.24 um 19:44 schrieb Vignesh Raghavendra:

On 28/10/24 22:49, Josua Mayer wrote:

quoted

Hi Geert, Vignesh,

Am 28.10.24 um 16:31 schrieb Vignesh Raghavendra:

quoted

On 25/10/24 19:27, Geert Uytterhoeven wrote:

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Hi Josua,

On Mon, Feb 19, 2024 at 4:05 PM Josua Mayer [off-list ref] wrote:

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HummingBoard-T features two M.2 connectors labeled "M1" and "M2".
The single SerDes lane of the SoC can be routed to either M1 pci-e
signals, or M2 usb-3 signals by a gpio-controlled mux.

Add overlays for each configuration.

Signed-off-by: Josua Mayer <redacted>

Thanks for your patch, which is now commit bbef42084cc170cb ("arm64:
dts: ti: hummingboard-t: add overlays for m.2 pci-e and usb-3") in v6.9.

quoted

--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am642-hummingboard-t-usb3.dtso

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Josua Mayer <josua@solid-run.com>
+ *
+ * Overlay for SolidRun AM642 HummingBoard-T to enable USB-3.1.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/phy/phy.h>
+
+#include "k3-serdes.h"
+
+&serdes0 {
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       serdes0_link: phy@0 {
+               reg = <0>;
+               cdns,num-lanes = <1>;
+               cdns,phy-type = <PHY_TYPE_USB3>;
+               #phy-cells = <0>;
+               resets = <&serdes_wiz0 1>;
+       };
+};
+
+&serdes_ln_ctrl {
+       idle-states = <AM64_SERDES0_LANE0_USB>;
+};
+
+&serdes_mux {
+       idle-state = <0>;
+};
+
+&usbss0 {
+       /delete-property/ ti,usb2-only;

/delete-property/ (and /delete-node/) to delete something in the base DTS
does not work.

My understanding is that flags are equivalent to boolean, i.e:

ti,usb2-only = <true>;
ti,usb2-only;

are equivalent.

If so, can we assign <false> within the overlay?

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Geert,

Thanks for the catching

Excellent spotting indeed.
I noticed this in passing about a week ago when I requested
Debian enable the necessary drivers in their distro kernel
(without understanding the root cause).

quoted

Joshua,

This overlay is pretty useless in light of above issue.  I intend to
just drop this file unless you convince me otherwise?

I would really prefer to fix it, or somehow replace with equivalent functionality.

My original proposal was having the board a dtsi, and the pci and usb3
variants as standalone dts.

Yeah, you would need a separate board dts for this profile. Please
propose a patch

Is there any chance of reassigning <false> and making an argument
that this should be fixed?

I find it frustrating that overlays can't override boolean properties,
and for consistency reasons I would otherwise change both
pcie and usb3 overlays to standalone dts.