On Sat, Aug 03, 2019 at 03:23:23PM +0200, Adam Borowski wrote: > On Fri, Aug 02, 2019 at 09:59:06PM +0200, Paul Menzel wrote: > > On 02.08.19 18:02, Greg Kroah-Hartman wrote: > > > On Fri, Aug 02, 2019 at 03:23:08PM +0200, Paul Menzel wrote: > > > > On a lot of devices, like servers, you have more than one serial console, > > > > and you do not always know, how they are numbered. Therefore, we start a > > > > console on ttyS0 and ttyS1. > > > > Because the cable is always connected to the port on the back side, and > > sometimes the port in the front has ID 0, and the one in the back 1, and > > other times vice versa. We do not want to track that, and it would be > > convenient to just write to both ports. > > Sounds like an XY problem then: what you want is not writing to all ports, > but to have the port assignments stable (see also: disk device reordering). You can get that information from the symlinks in /dev/serial/ which udev creates.
