Re: [PATCH 2/3] ARM: dts: imx6ulz-bsh-smm-m2: Enable uart2

Michael Nazzareno Trimarchi
2025-05-16T10:14:19Z

Hi

On Fri, May 16, 2025 at 4:56 AM Peng Fan <peng.fan@oss.nxp.com> wrote:
>
> On Wed, May 14, 2025 at 09:05:34AM +0200, Dario Binacchi wrote:
> >From: Wolfgang Birkner <wolfgang.birkner@bshg.com>
> >
> >uart2 is used as wake up source.
> >
> >Signed-off-by: Wolfgang Birkner <wolfgang.birkner@bshg.com>
> >Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> >---
> >
> > arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> >diff --git a/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts b/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts
> >index 5c32d1e3675c..fff21f28c552 100644
> >--- a/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts
> >+++ b/arch/arm/boot/dts/nxp/imx/imx6ulz-bsh-smm-m2.dts
> >@@ -37,6 +37,10 @@ &snvs_poweroff {
> > status = "okay";
> > };
> >
> >+&uart2 {
> >+ status = "okay";
> >+};
>
> No need pinctrl settings?
>

We found out that in imx6ulz, if we don't enable wakeup on uart2 (or
other uarts that do not conflict on pinout) we are not able to wake up
from uart4, which is the console.
According to the TRM and the code everything look fine but the real
result it's we stuck in suspend

Here is how we are able to resume.

uart2
echo enabled > wakeup
uart4
echo enabled > wakeup

Michael

> Regards,
> Peng
>
> >+
> > &uart3 {
> > pinctrl-names = "default";
> > pinctrl-0 = <&pinctrl_uart3>;
> >--
> >2.43.0
> >
> >base-commit: e9565e23cd89d4d5cd4388f8742130be1d6f182d
> >branch: bsh-202505-imx6ulz_smm_m2
>
>

--
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael@amarulasolutions.com
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