Document TUNE_1542.

[unix-history] / sys / doc / options.texi

diff --git a/sys/doc/options.texi b/sys/doc/options.texi
index e39bb7f..cdf3511 100644 (file)
--- a/sys/doc/options.texi
+++ b/sys/doc/options.texi
@@ -10,7 +10,7 @@
 @c %**end of header
 
 @ifinfo
 @c %**end of header
 
 @ifinfo

-$Id: options.texi,v 1.1 1994/03/30 20:36:34 wollman Exp $
+$Id: options.texi,v 1.2 1994/04/03 18:38:48 wollman Exp $

 
 This file documents the configuration options available in the FreeBSD
 operating system.
 
 This file documents the configuration options available in the FreeBSD
 operating system.


@@ -645,7 +645,9 @@ listed in this section.  It provides the basic support for the ISA-bus
 glue logic, including DMA and autoconfiguration.
 
 @item controller aha0 at isa? port "IO_AHA0" bio irq 11 drq 5 vector ahaintr
 glue logic, including DMA and autoconfiguration.
 
 @item controller aha0 at isa? port "IO_AHA0" bio irq 11 drq 5 vector ahaintr

+@item options "TUNE_1542"

 @findex aha
 @findex aha

+@findex TUNE_1542

 @cindex Adaptec 154x
 @cindex SCSI host adaptors
 The @samp{aha} device supports the Adaptec 154x series of SCSI
 @cindex Adaptec 154x
 @cindex SCSI host adaptors
 The @samp{aha} device supports the Adaptec 154x series of SCSI


@@ -655,6 +657,13 @@ This device is included in the @samp{GENERICAH} distribution kernel.
 The @samp{scbus} device (@pxref{SCSI}) is a prerequisite for this
 device.
 
 The @samp{scbus} device (@pxref{SCSI}) is a prerequisite for this
 device.
 

+Some older versions of this code would attempt to set the controller's
+bus access speed to the fastest possible without losing data; we have
+found that this makes the driver unusable for some users.  If you wish
+to enable this optimization, or if you suspect that your SCSI transfers
+are running slower than they should, then you can use the @samp{TUNE_1542}
+option to enable bus-timing detection.
+

 @item controller bt0 at isa? port "IO_BT0" bio irq 12 vector btintr
 @findex bt
 @cindex Bustek 742
 @item controller bt0 at isa? port "IO_BT0" bio irq 12 vector btintr
 @findex bt
 @cindex Bustek 742