Re: [PATCH] arm64: dts: verdin-imx8mm: add otg2 pd to usbphy

[Frieder Schrempf <frieder.schrempf@kontron.de>]

+CC: Li Jun, Jacky Bai, Lucas Stach

Hi Philippe,

Am 22.07.22 um 09:55 schrieb Philippe Schenker:
> From: Philippe Schenker <philippe.schenker@toradex.com>
> 
> The Verdin iMX8M Mini System on Module does not have VBUS signal
> connected on Verdin USB_2 (usbotg2). On Verdin Development board this is
> no problem, as we have connected a USB-Hub that is always connected.
> 
> However, if Verdin USB_2 is desired to be used as a single USB-Host port
> the chipidea driver does not detect if a USB device is plugged into this
> port, due to runtime pm shutting down the PHY.
> 
> Add the power-domain &pgc_otg2 to &usbphynop2 in order to detect
> plugging events and enumerate the usb device.
> 
> Fixes: 6a57f224f734 ("arm64: dts: freescale: add initial support for verdin imx8m mini")
> Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>

I'm probably having the same issue on our hardware. There was a previous
attempt to fix this globally for all the i.MX8MM boards here: [1].

Unfortunately this didn't seem to work as intended in my case (see
discussion for that patch). Looking at your patch I wonder if not having
the vcc-supply for the usbphynop causes problems in my case. Do you
happen to know the effect of adding the regulator here? I don't see this
in any other i.MX8MM board devicetree.

Could you test Li's patch instead of this board specific fix and see if
it works for you? On your hardware, do you have an always-on device on
the usbotg1 port? If yes, does the detection on the usbotg2 port still
work if the usbotg1 port is disabled in the devicetree?

Thanks
Frieder

[1]
https://lore.kernel.org/linux-arm-kernel/f4879eed-79a7-3a1a-8dd0-c1a6ed367f34@kontron.de

> 
> ---
> 
>  arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> index eafa88d980b3..197da74837ca 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> @@ -737,6 +737,7 @@ &usbphynop1 {
>  };
>  
>  &usbphynop2 {
> +	power-domains = <&pgc_otg2>;
>  	vcc-supply = <&reg_vdd_3v3>;
>  };
>