[PATCH] mx6cuboxi: fix ethernet after synchronise device-tree
Josua Mayer
josua at solid-run.com
Wed Mar 27 14:20:04 CET 2024
Am 27.03.24 um 13:17 schrieb Christian Gmeiner:
> Hi Josua
>
> My bisect showed me that after a device-tree sync the ethernet broke.
>
>> please take a look at this patch, I suspect it will (hack-)fix your
>> ethernet issue.
>>
> Yes.. it fixes the problem I am seeing.
>
>> Unfortunately I had no time to revisit this yet and implement a correct solution.
>>
> Would it be okay for you if I look into a proper solution?
Sure. I am swamped by other products at the moment.
However I will provide a rough overview what needs to be done:
Background: i.MX6 SoMs originally had a an atheros phy at unstable address,
either 0 or 4 depending on electrical noise on floating configuration signals.
Linux had solved this by placing 2 phy nodes in device-tree.
During boot the kernel would attempt in order to probe the phys,
then link the successful one to the ethernet netdev.
As a side-effect there is always an error in the kernel log for one of the
addresses.
U-Boot had something similar in that with a special address (I think 0xff)
in device-tree, the code will probe mdio bus for all addresses, but only
for a single phy node in dts.
With release of SoM 2.0 we changed to an analog devices phy at address 1,
which most importantly uses a different driver, and requires a different description
in device-tree.
When adding this new phy, as a third node in device-tree, kernel maintainers
requested a better solution, and we got u-boot to runtime patch dtb to update
status properties of the dtb for linux, after probing mdio bus for phys.
Now - what u-boot needs to do is probe the mdio bus, and then runtime-patch its own DTB.
Either with status properties, or for adding the phy-handle property (not sure which method will work).
This somehow has to happen after probing mdio driver, but before probing ethernet driver.
> I have a
> handful of such devices here
> that are already or will be used in a CI farm so I am interested in
> using the latest U-Boot for them.
>
>> sincerely
>> Josua Mayer
>>
>> Am 28.07.22 um 09:08 schrieb Josua Mayer:
>>> Please hold off merging this patch until someone tested it, I can not do so this week.
>>> @Tom Can you confirm if this fixes the networking on your Cubox?
>>> Also note that the phy-handle property may or may not be required, I am not sure.
>>>
>>> sincerely
>>> Josua Mayer
>>>
>>> On Thu, Jul 28, 2022 at 7:05 AM Josua Mayer <josua at solid-run.com> wrote:
>>>
>>> The i.MX6 Cubox-i and HummingBoards can have different PHYs at varying
>>> addresses. U-Boot needs to auto-detect which phy is actually present,
>>> and at which address it is responding.
>>>
>>> Auto-detection from multiple phy nodes specified in device-tree does not
>>> currently work correct. As a work-around merge all three possible phys
>>> into one node with the special address 0xffffffff which indicates to the
>>> generic phy driver to probe all addresses.
>>> Also fixup this fake address before booting Linux, *if* booting with
>>> U-Boot's internal dtb.
>>>
>>> Signed-off-by: Josua Mayer <josua at solid-run.com>
>>> Fixes: d0399a46e7cd
>>> ---
>>> arch/arm/dts/imx6qdl-sr-som.dtsi | 30 +++++++++-------------------
>>> board/solidrun/mx6cuboxi/mx6cuboxi.c | 6 +++++-
>>> 2 files changed, 14 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/arch/arm/dts/imx6qdl-sr-som.dtsi b/arch/arm/dts/imx6qdl-sr-som.dtsi
>>> index ce543e325c..2d7cbc26b3 100644
>>> ---_a/arch/arm/dts/imx6qdl-sr-som.dtsi
>>> +++ b/arch/arm/dts/imx6qdl-sr-som.dtsi
>>> @@ -53,6 +53,7 @@
>>> &fec {
>>> pinctrl-names = "default";
>>> pinctrl-0 = <&pinctrl_microsom_enet_ar8035>;
>>> + phy-handle = <&phy>;
>>> phy-mode = "rgmii-id";
>>>
>>> /*
>>> @@ -68,30 +69,17 @@
>>> #address-cells = <1>;
>>> #size-cells = <0>;
>>>
>>> - /*
>>> - * The PHY can appear at either address 0 or 4 due to the
>>> - * configuration (LED) pin not being pulled sufficiently.
>>> - */
>>> - ethernet-phy at 0 {
>>> - reg = <0>;
>>> + phy: ethernet-phy at 0 {
>>> + /*
>>> + * The PHY can appear either:
>>> + * - AR8035: at address 0 or 4
>>> + * - ADIN1300: at address 1
>>> + * Actual address being detected at runtime.
>>> + */
>>> + reg = <0xffffffff>;
>>> qca,clk-out-frequency = <125000000>;
>>> qca,smarteee-tw-us-1g = <24>;
>>> - };
>>> -
>>> - ethernet-phy at 4 {
>>> - reg = <4>;
>>> - qca,clk-out-frequency = <125000000>;
>>> - qca,smarteee-tw-us-1g = <24>;
>>> - };
>>> -
>>> - /*
>>> - * ADIN1300 (som rev 1.9 or later) is always at address 1. It
>>> - * will be enabled automatically by U-Boot if detected.
>>> - */
>>> - ethernet-phy at 1 {
>>> - reg = <1>;
>>> adi,phy-output-clock = "125mhz-free-running";
>>> - status = "disabled";
>>> };
>>> };
>>> };
>>> diff --git a/board/solidrun/mx6cuboxi/mx6cuboxi.c b/board/solidrun/mx6cuboxi/mx6cuboxi.c
>>> index debf4f6a3b..52172a03b1 100644
>>> ---_a/board/solidrun/mx6cuboxi/mx6cuboxi.c
>>> +++ b/board/solidrun/mx6cuboxi/mx6cuboxi.c
>>> @@ -446,7 +446,7 @@ static int find_ethernet_phy(void)
>>> */
>>> int ft_board_setup(void *fdt, struct bd_info *bd)
>>> {
>>> - int node_phy0, node_phy1, node_phy4;
>>> + int node_phy, node_phy0, node_phy1, node_phy4;
>>> int ret, phy;
>>> bool enable_phy0 = false, enable_phy1 = false, enable_phy4 = false;
>>> enum board_type board;
>>> @@ -478,6 +478,10 @@ int ft_board_setup(void *fdt, struct bd_info *bd)
>>> return 0;
>>> }
>>>
>>> + // update U-Boot's own unified phy node phy address, if present
>>> + node_phy = fdt_path_offset(fdt, "/soc/bus at 2100000/ethernet at 2188000/mdio/phy");
>>> + ret = fdt_setprop_u32(fdt, node_phy, "reg", phy);
>>> +
>>> // update all phy nodes status
>>> node_phy0 = fdt_path_offset(fdt, "/soc/bus at 2100000/ethernet at 2188000/mdio/ethernet-phy at 0");
>>> ret = fdt_setprop_string(fdt, node_phy0, "status", enable_phy0 ? "okay" : "disabled");
>>> --_
>>> 2.37.1
>>>
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