Re: [PATCH v7 4/4] arm64: dts: ti: hummingboard-t: add overlays for m.2 pci-e and usb-3

[Vignesh Raghavendra <vigneshr@ti.com>]

On 28/10/24 22:49, Josua Mayer wrote:
> Hi Geert, Vignesh,
> 
> Am 28.10.24 um 16:31 schrieb Vignesh Raghavendra:
>>
>> On 25/10/24 19:27, Geert Uytterhoeven wrote:
>>> Hi Josua,
>>>
>>> On Mon, Feb 19, 2024 at 4:05 PM Josua Mayer <josua@solid-run.com> wrote:
>>>> 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 <josua@solid-run.com>
>>> 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.
>>>
>>>> --- /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?
> 
>> 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).
>>
>> 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

-- 
Regards
Vignesh