[PATCH] mx6cuboxi: fix ethernet after synchronise device-tree
Christian Gmeiner
christian.gmeiner at gmail.com
Wed Mar 27 16:55:47 CET 2024
Hi Josua
> > 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.
>
Would it be possible to set those configuration signals from the MX6
to a defined state and
then toggle the PHY reset , to force correct PHY address?
> 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.
>
Got it.
>
> 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).
>
We could patch DTB in SPL for U-Boot proper but doing a mdio scan in
SPL looks like a lot of work. Do
you know if there is a pull up/down resistor etc. that I could use to
detect pre SoM 2.0 and SoM 2.0?
Is this what board_type() does?
Is HummingBoard2 == SoM 2.0?
> 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
> >>>
--
greets
--
Christian Gmeiner, MSc
https://christian-gmeiner.info/privacypolicy
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