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Document new config flag for lost output interrupts.

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Treat the intitial state device less negatively.  It is essential for
initializing nonstandard flags such as crtscts.

Delete anachronisms.
This commit is contained in:
bde 1995-06-26 06:05:30 +00:00
parent b10dad9586
commit d8fb7815a1
2 changed files with 22 additions and 16 deletions
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19
share/man/man4/man4.i386/sio.4
View File

@ -34,7 +34,7 @@
.\"
.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91
.\" from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
.\" $Id: sio.4,v 1.14 1994/12/05 00:02:38 ache Exp $
.\" $Id: sio.4,v 1.15 1994/12/06 20:14:30 bde Exp $
.\"
.Dd June 3, 1994
.Dt SIO 4 i386
@ -71,6 +71,8 @@ Meaning of \fBflags\fR:
.br
\fB0x0004\fR no AST/4 compatible IRQ control register
.br
\fB0x0008\fR recover sooner from lost output interrupts
.br
\fB0x0080\fR enable diagnostics in probe
.br
\fB0x\fI??\fB00\fR minor number of master port
@ -218,14 +220,17 @@ may be locked by setting the corresponding value in the lock-state
device to any nonzero value.
.sp
Correct programs talking to correctly wired external devices
work with arbitrary initial states and almost no locking,
work with almost arbitrary initial states and almost no locking,
but other setups may benefit from changing some of the default
initial state and locking the state.
In particular, the initial states for non (POSIX) standard flags
should be set to suit the devices attached and may need to be
locked to prevent buggy programs from changing them.
E.g., CRTSCTS should be locked on for devices that support
RTS/CTS handshaking at all times and off for devices that don't
support it at all. CLOCAL should be locked on for devices
that don't support carrier. HUPCL may be locked off if you don't
want to hang up for reason. In general, very bad things happen
want to hang up for some reason. In general, very bad things happen
if something is locked to the wrong state, and things should not
be locked for devices that support more than one setting. The
CLOCAL flag on callin ports should be locked off for logins
@ -287,9 +292,9 @@ driver is derived from the
driver and is
.Ud
.Sh BUGS
Data loss is not nearly as likely on busy systems as it is with the
.Xr com 4
driver but it can still occur at very high baud rates on slow systems.
Data loss may occur at very high baud rates on slow systems,
or with too many ports on any system,
or on heavily loaded systems when crtscts cannot be used.
The use of NS16550A's reduces system load and helps to avoid data loss.
.Pp
Stay away from plain NS16550's. These are early
@ -307,6 +312,4 @@ be set to use interrupt sharing. AST/4-like interrupt sharing is only used when
AST/4 cards are installed in the same system. The sio driver does not
support more than 1 AST/4 on one IRQ.
.Pp
Hardwired terminals should not have different device names.
.Pp
The examples in the synopsis are too vendor-specific.

19
share/man/man4/sio.4
View File

@ -34,7 +34,7 @@
.\"
.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91
.\" from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
.\" $Id: sio.4,v 1.14 1994/12/05 00:02:38 ache Exp $
.\" $Id: sio.4,v 1.15 1994/12/06 20:14:30 bde Exp $
.\"
.Dd June 3, 1994
.Dt SIO 4 i386
@ -71,6 +71,8 @@ Meaning of \fBflags\fR:
.br
\fB0x0004\fR no AST/4 compatible IRQ control register
.br
\fB0x0008\fR recover sooner from lost output interrupts
.br
\fB0x0080\fR enable diagnostics in probe
.br
\fB0x\fI??\fB00\fR minor number of master port
@ -218,14 +220,17 @@ may be locked by setting the corresponding value in the lock-state
device to any nonzero value.
.sp
Correct programs talking to correctly wired external devices
work with arbitrary initial states and almost no locking,
work with almost arbitrary initial states and almost no locking,
but other setups may benefit from changing some of the default
initial state and locking the state.
In particular, the initial states for non (POSIX) standard flags
should be set to suit the devices attached and may need to be
locked to prevent buggy programs from changing them.
E.g., CRTSCTS should be locked on for devices that support
RTS/CTS handshaking at all times and off for devices that don't
support it at all. CLOCAL should be locked on for devices
that don't support carrier. HUPCL may be locked off if you don't
want to hang up for reason. In general, very bad things happen
want to hang up for some reason. In general, very bad things happen
if something is locked to the wrong state, and things should not
be locked for devices that support more than one setting. The
CLOCAL flag on callin ports should be locked off for logins
@ -287,9 +292,9 @@ driver is derived from the
driver and is
.Ud
.Sh BUGS
Data loss is not nearly as likely on busy systems as it is with the
.Xr com 4
driver but it can still occur at very high baud rates on slow systems.
Data loss may occur at very high baud rates on slow systems,
or with too many ports on any system,
or on heavily loaded systems when crtscts cannot be used.
The use of NS16550A's reduces system load and helps to avoid data loss.
.Pp
Stay away from plain NS16550's. These are early
@ -307,6 +312,4 @@ be set to use interrupt sharing. AST/4-like interrupt sharing is only used when
AST/4 cards are installed in the same system. The sio driver does not
support more than 1 AST/4 on one IRQ.
.Pp
Hardwired terminals should not have different device names.
.Pp
The examples in the synopsis are too vendor-specific.