Re: [RFC PATCH 1/2] serial: core: Move tty and serdev to be children of serial core port device

From: Tony Lindgren
Date: Wed Oct 25 2023 - 02:52:00 EST


* Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [231024 14:01]:
> On Tue, Oct 24, 2023 at 03:29:55PM +0300, Tony Lindgren wrote:
> > * Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [231024 11:52]:
> > > What does this change the sysfs tree to look like?
> >
> > On x86 qemu for the ttys:
> >
> > # find /sys -name tty
> > /sys/class/tty
> > /sys/class/tty/tty
> > /sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty
> > /sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty
> > /sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty
> > /sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty
> > /sys/devices/virtual/tty
> > /sys/devices/virtual/tty/tty
>
> A diff of before vs. after would make more sense for those of us who
> don't have your same system configuration :)

Here's the diff of the same command before and after:

--- /tmp/before 2023-10-25 09:45:12.197283690 +0300
+++ /tmp/after 2023-10-25 09:43:30.681797899 +0300
@@ -1,7 +1,9 @@
# find /sys -name tty
/sys/class/tty
/sys/class/tty/tty
-/sys/devices/pnp0/00:04/tty
-/sys/devices/platform/serial8250/tty
+/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty
/sys/devices/virtual/tty
/sys/devices/virtual/tty/tty

There are multiple ports claimed by serial8250. So I think the new sysfs
output is correct showing more ttys. If there's some reason why serial8250
should only have one tty and this output is not correct let me know too..

Regards,

Tony