cvs commit: src/sys/conf NOTES options src/share/man/man4 sio.4 src/sys/dev/sio sio.c

[Doug Ambrisko]

Bruce Evans writes:
| On Mon, 3 May 2004, Doug Ambrisko wrote:
| 
| > ambrisko    2004/05/03 15:35:28 PDT
| >
| >   FreeBSD src repository
| >
| >   Modified files:
| >     sys/conf             NOTES options
| >     share/man/man4       sio.4
| >     sys/dev/sio          sio.c
| >   Log:
| >   Remove new options and my prevention of system freeze when the sio probe
| >   returns okay when HW probe fails.  This happens when comconsole flag is
| >   set but VGA console is used instead.
| >
| >   Back out requested by:  bde (He will be looking at other solutions from scratch)
| 
| I think you mean that the freeze happens when the comconsole flag is set
| but the VGA console is _not_ used instead despite there being no usable
| serial console.  Neither the boot blocks not sio check whether the

No.  Okay there are 2 potential freezes.  Once during boot the
other when the system is up:
    1)	If in comconsole mode and the 0x10 flags are set the system
	doesn't boot.  I'm basically okay with that and offered a
	different type of work around for that that we use when
	the next one to try is probed before the failed one.
    2)	If in vidconsole mode and the 0x10 flags are set the serial
	port in dmesg says if failed to probe but since the 0x10 flags
	is set it says the serial port is there even though it is
	not a console.  It also says it is 8250 UART.  Then you 
	write something out that "probed" port and the system hangs 
	from user-land :-(

| Network and/or nonstandard boot blocks apparently set the comconsole
| flag without initializing a serial console (because they don't support
| using one and don't know that they are supposed to initialize one for
| the kernel?).  This can cause garbled i/o.

Yep, which is annoying so it was easy to provide a simple kernel option
to force it to CONSPEED no matter what and have a working console.
 
| There are also problems with multiple enabled console or debugger ports...
| See PR 65278 for the main one.

This wasn't my concern when adding this.

Doug A.