[systemd-devel] systemd doesn't see ttyPS0 devices from udev

[Lennart Poettering]

On Di, 22.09.20 15:34, Andrei Borzenkov (arvidjaar at gmail.com) wrote:
65;6003;1c
> On Tue, Sep 22, 2020 at 2:53 PM Mantas Mikulėnas <grawity at gmail.com> wrote:
> >
> > On Tue, Sep 22, 2020 at 1:46 PM Andrei Borzenkov <arvidjaar at gmail.com> wrote:
> >>
> >> On Tue, Sep 22, 2020 at 1:35 PM ZhouPeng <zhoupengwork01 at 163.com> wrote:
> >> >
> >> > Hi all,
> >> >
> >> > When I use Fedora image as rootfs on Xilinx PYNQ-Z2, I encountered the issue  when use the /dev/ttyPS0.
> >> > I think the issue is because systemd and udev on fedora can didn't detect ttyPS0 properly. Do I need to install any other package or do some special configuration?
> >> >
> >> > **systemd version the issue has been seen with**
> >> > udevadm --version
> >> > 237
> >> > systemd-udev.riscv64                     237-1.0.riscv64.fc28
> >> >
> >> >
> >> > **Unexpected behaviour you saw**
> >> > We can see ttyPS0 boots ok in the kernel boot period:
> >> > [    0.180000] console [ttyPS0] enabledat MMIO 0xe0000000 (irq = 2, base_baud = 6250000) is a xuartps
> >> > [    0.180000] console [ttyPS0] enabled
> >> >
> >> > But, when boot into systemd, it failed on dev ttyPS0:
> >> > [ TIME ] Timed out waiting for device dev-ttyPS0.device. // **here**
> >>
> >> systemd only monitors for devices with "sysemd" tag. Tags are assigned
> >> by udev rules. You should add rule to assign tag to ttyPS0. I have no
> >> idea what it is, but something like
> >>
> >> ACTION!="remove", KERNEL=="ttyPS0", TAG+="systemd"
> >>
> >> should do it. Whether this should go upstream depends on how common
> >> this device is.
> >
> >
> > Well yes, but that should have been already covered by the existing upstream rules:
> >
> > 99-systemd.rules:12:SUBSYSTEM=="tty", KERNEL=="tty[a-zA-Z]*|hvc*|xvc*|hvsi*|ttysclp*|sclp_line*|3270/tty[0-9]*", TAG+="systemd"
> >
>
> Are you sure ttyPS0 has the "tty" subsystem?

What does "udevadm info -a /dev/ttyPS0" output?

Lennart

--
Lennart Poettering, Berlin