Updated the BUGS section. BREAK is now implemented.

Don't document non-bugs in the BUGS section, or anywhere else.  It
is not a bug to drop data when overloaded.  The compile-time tuning
options turned out to be not very useful, and aren't supported
offically.

Documented the not so new option CY_PCI_FASTINTR.
This commit is contained in:
Bruce Evans 1999-06-14 15:10:35 +00:00
parent 33d56839e3
commit e343fb02c3
2 changed files with 28 additions and 56 deletions

View File

@ -35,15 +35,16 @@
.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91
.\" from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
.\" from: sio.4,v 1.16 1995/06/26 06:05:30 bde Exp $
.\" $Id: cy.4,v 1.9 1998/10/22 14:51:19 bde Exp $
.\" $Id: cy.4,v 1.10 1999/05/20 09:55:53 yokota Exp $
.\"
.Dd October 10, 1995
.Dd June 14, 1999
.Dt CY 4 i386
.Os FreeBSD
.Sh NAME
.Nm cy
.Nd Cyclades Cyclom-Y serial driver
.Sh SYNOPSIS
.Cd "options" \&"CY_PCI_FASTINTR\&"
.Cd "device cy0 at isa? irq 10 iomem 0xd4000 iosiz 0x2000"
.Cd "device cy1 at isa? irq 11 iomem 0xd6000 iosiz 0x2000"
.Pp
@ -143,6 +144,17 @@ be locked for devices that support more than one setting. The
CLOCAL flag on callin ports should be locked off for logins
to avoid certain security holes, but this needs to be done by
getty if the callin port is used for anything else.
.Ss Kernel Configuration Options
The
.Em CY_PCI_FASTINTR
option should be used to avoid suboptimal interrupt handling for
PCI Cyclades boards.
The PCI BIOS must be configured with the
.Nm
interrupt not shared with any other active device
for this option to work.
This option is not the default because it is currently harmful in
certain cases where it does not work.
.Sh FILES
.\" XXX more cloning: s/d/c/g and add a ? for the card number.
.Bl -tag -width /dev/ttyic?? -compact
@ -206,30 +218,4 @@ driver and the NetBSD
driver and is
.Ud
.Sh BUGS
BREAK is not yet implemented.
.Pp
Serial consoles are not implemented.
.Pp
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.
.Pp
There are too many compile-time-only flags.
The CD1400 has slightly smaller fifos than the NS16550 (12 bytes
instead of 16), so it needs pseudo-dma more than a NS16550. The
default configuration is optimized for generality at about a 30%
relative cost in efficiency. These compile-time defines may be
changed for higher efficiency:
.Pp
RxFifoThreshold: default 6; on a 486DX-33, this works for 8 ports
talking to each other at 115200 bps; 11 works for 8 ports talking
to each other at 57600 bps. The low threshold is not for
.Tn FreeBSD ,
it's for the CD1400, which can't really keep up with 115200 bps.
.Pp
PollMode: required for Cyclom-16Y's; costs 10-20% relative efficiency
on Cyclom-8Y's (more with a low RxFifoThreshold).
.Pp
SOFT_HOTCHAR: required in addition to the small RxFifoThreshold
to avoid overruns with SLIP and PPP for 8 ports at 115200 bps.
Costs 5% relative efficiency.

View File

@ -35,15 +35,16 @@
.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91
.\" from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
.\" from: sio.4,v 1.16 1995/06/26 06:05:30 bde Exp $
.\" $Id: cy.4,v 1.9 1998/10/22 14:51:19 bde Exp $
.\" $Id: cy.4,v 1.10 1999/05/20 09:55:53 yokota Exp $
.\"
.Dd October 10, 1995
.Dd June 14, 1999
.Dt CY 4 i386
.Os FreeBSD
.Sh NAME
.Nm cy
.Nd Cyclades Cyclom-Y serial driver
.Sh SYNOPSIS
.Cd "options" \&"CY_PCI_FASTINTR\&"
.Cd "device cy0 at isa? irq 10 iomem 0xd4000 iosiz 0x2000"
.Cd "device cy1 at isa? irq 11 iomem 0xd6000 iosiz 0x2000"
.Pp
@ -143,6 +144,17 @@ be locked for devices that support more than one setting. The
CLOCAL flag on callin ports should be locked off for logins
to avoid certain security holes, but this needs to be done by
getty if the callin port is used for anything else.
.Ss Kernel Configuration Options
The
.Em CY_PCI_FASTINTR
option should be used to avoid suboptimal interrupt handling for
PCI Cyclades boards.
The PCI BIOS must be configured with the
.Nm
interrupt not shared with any other active device
for this option to work.
This option is not the default because it is currently harmful in
certain cases where it does not work.
.Sh FILES
.\" XXX more cloning: s/d/c/g and add a ? for the card number.
.Bl -tag -width /dev/ttyic?? -compact
@ -206,30 +218,4 @@ driver and the NetBSD
driver and is
.Ud
.Sh BUGS
BREAK is not yet implemented.
.Pp
Serial consoles are not implemented.
.Pp
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.
.Pp
There are too many compile-time-only flags.
The CD1400 has slightly smaller fifos than the NS16550 (12 bytes
instead of 16), so it needs pseudo-dma more than a NS16550. The
default configuration is optimized for generality at about a 30%
relative cost in efficiency. These compile-time defines may be
changed for higher efficiency:
.Pp
RxFifoThreshold: default 6; on a 486DX-33, this works for 8 ports
talking to each other at 115200 bps; 11 works for 8 ports talking
to each other at 57600 bps. The low threshold is not for
.Tn FreeBSD ,
it's for the CD1400, which can't really keep up with 115200 bps.
.Pp
PollMode: required for Cyclom-16Y's; costs 10-20% relative efficiency
on Cyclom-8Y's (more with a low RxFifoThreshold).
.Pp
SOFT_HOTCHAR: required in addition to the small RxFifoThreshold
to avoid overruns with SLIP and PPP for 8 ports at 115200 bps.
Costs 5% relative efficiency.