Hi,

I'm not really experiencing problems with respect to what I'm
reporting here, but I was reading the code and I might have spotted a
problem in the IDE driver in 2.0.36:


static int lba_capacity_is_ok (struct hd_driveid *id)
{
        unsigned long lba_sects   = id->lba_capacity;
        unsigned long chs_sects   = id->cyls * id->heads * id->sectors;
        unsigned long _10_percent = chs_sects / 10;

        /* very large drives (8GB+) may lie about the number of cylinders */
        if (id->cyls == 16383 && id->heads == 16 && id->sectors == 63 && lba_sects > chs_se
cts) {
                id->cyls = lba_sects / (16 * 63); /* correct cyls */
                return 1;       /* lba_capacity is our only option */
        }
        /* perform a rough sanity check on lba_sects:  within 10% is "okay" */
        if ((lba_sects - chs_sects) < _10_percent)
                return 1;       /* lba_capacity is good */

        /* some drives have the word order reversed */
        lba_sects = (lba_sects << 16) | (lba_sects >> 16);
        if ((lba_sects - chs_sects) < _10_percent) {
                id->lba_capacity = lba_sects;   /* fix it */
                return 1;       /* lba_capacity is (now) good */
        }
        return 0;       /* lba_capacity value is bad */
}


As "lba_sects" is defined a "long", this will be 64 bits on
Alpha. Swapping the words with the "(lba_sects << 16) | (lba_sects >>
16);" wont work: you're counting on 32bit arithmetic. I recommend
adding the appropriate & 0xffff's in there...

I can imagine that code not getting enough testing... :-) 
(as not many alpha-owners are going to have an odd IDE disk like that)


Regards,

			Roger. 




-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
------ Microsoft SELLS you Windows, Linux GIVES you the whole house ------


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