Messages in this thread |  | | From | (Joachim Achtzehnter) | Subject | Re: AHA2940UW UltraSCSI option | Date | 12 Jan 1997 21:00:44 GMT |
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[Posted and mailed]
In article <198165FC2@ekspress.ee>, "Magnus Hiie" <Mgn@ekspress.ee> writes: > ... found the following line in drivers/scsi/aic7xxx.c: > > static int aic7xxx_enable_ultra = 0; /* enable ultra SCSI speeds */ > > So, it appears that I've been using Linux without UltraSCSI enabled.
You need to enable UltraSCSI speeds in the board setup (you get there by pressing certain keys during boot). Then the Linux aic7xxx driver automatically enables UltraSCSI support. You can verify this by looking at the file /proc/scsi/aic7xxx/0.
Note, that certain other features are compile options and appear to be disabled by default in 2.0.27, namely tagged queuing, and SCB paging. Also the number of SCBs per command is defaulted to 2, but can be increased by changing a define in the aic7xxx.c file. I don't know whether the default values of these parameters imply that other settings are flaky, or don't improve performance. Since yesterday I've been running a kernel with tagged queuing and 8 SCBs per command without problems, but also without noticable difference in performance.
Joachim
-- ______ email: joachim@wimsey.ca (home) joachim@mercury.bc.ca (work) WWW: http://www.wimsey.ca/~joachim/
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