Messages in this thread | | | Date | Sat, 10 Jul 1999 14:32:56 +1000 | From | Nick Andrew <> | Subject | Re: [PATCH] Ext.BIOS Translation for AHA-1542 |
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On Sat, Jul 10, 1999 at 04:32:26AM +0200, Andries.Brouwer@cwi.nl wrote: > > - if(mbenable_result[1] & 0x03) retval = BIOS_TRANSLATION_25563; > > + if((mbenable_result[0] & 0x08) && (mbenable_result[1] & 0x03)) > > + retval = BIOS_TRANSLATION_25563; > > Interesting. As far as I know, the possible values of the pair > (mbenable_result[0], mbenable_result[1]) > (the two bytes resulting from the CMD_EXTBIOS command; the name is misleading) > are (0,0), (0,2), (8,1) and (8,2) on a AHA1542CF (or AHA1542CP). > > We want BIOS_TRANSLATION_25563 if and only if mbenable_result[0] equals 8. > So, I think the patch is correct (but needlessly complicated) > for AHA1542CF. Why do you test `(mbenable_result[1] & 0x03)' ?
That test was already there. I don't know under what circumstances (if any) it is correct. So I left it in, and added the test which worked under both the 1542CF and 1542CP controllers I had.
> Last year Nick Andrew compared AHA1542CF with AHA1542CP > and reported that the second byte equals 2 on a AHA1542CP > when a big disk is present. Nick - do you recall your precise setup?
Unfortunately I cannot tell you the exact controller revision as things have been moved around since then. I got annoyed at the unwanted 255x63 geometry and swapped controllers with test kernels until I was satisfied that my fix was correct.
> Did you have a single disk? And what is `big'?
Yes. The disk is probably a Seagate ST34572N (~4 gigs).
> Did you try to vary b) and c) ?
No.
> I find (0,2) also on AHA1542CF where you only got it on AHA1542CP.
If you like I can pull out a few controllers and test again. I should have a few spare (soon afterward I "discovered" that the AIC7xxx controller performance leaves the 1542 series for dead).
Nick. -- Zeta Internet SP4 Fax: +61-2-9233-6545 Voice: 9231-9400 G.P.O. Box 3400, Sydney NSW 1043 http://www.zeta.org.au/
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