On Fri, Dec 22, 2023 at 07:22:19AM +0000, Miod Vallat wrote: > > Ah yes, but that is a good thing. Because the Pi's have both > > pluart(4) and com(4) serial ports. So we don't really want pluart(4) > > to steal the com(4) major if it isn't the serial console. > > According to dmesg, Pi (at least 3b and 4) only have pluart, and no com.
the com(4) is "brcm,bcm2835-aux-uart" no longer the console after: "date: 2019/11/17 06:03:39; author: jsg; state: Exp; lines: +9 -2; commitid: RNzxIO92MIKR4uhW; Use disable-bt overlay with raspberry pi so the pl011 will be used as console uart instead of the 'mini uart' a quirky 8250 alike which lacks flow control and break detection. By default the pl011 is used for bluetooth. The pins the console is on do not change. When com(4) takes over the console with the mini uart on rpi3 I see noise before output resumes and can't interact with the console after it has booted. With pluart(4) as console everything is fine." > > > This major stealing has been bothering me since a long a time. Should > > we try to kill it? We'd need to come up with a sensible device naming > > scheme though that leaves us room for expansion if we have more > > drivers. > > Yes, this is horrible and should get removed - but then existing users > of pluart with tty00 would need to change their configuration. The diff > I sent uses ttyP0 (P for "pluart") but any other letter would be fine > (except for C used by wsdisplay and U used by ucom). > >
