Padraig.
Richard Smith wrote:
> I spent most of the day today trying to track down why the embedded system I am working
> on would not recognize hdb on boot. It refused to show in the devices list even though I
> specifically told the kernel it existed with the hdb=c,h,s option.
>
> After working on what seemed like a hardware problem for quite a while I finally decided
> that there must be something flaky in the ide driver code and began to add some debug
> printk's
>
> In which I found the following in ide.c:
>
> /*
> * CompactFlash cards and their brethern pretend to be removable hard disks,
> * except:
> * (1) they never have a slave unit, and
> * (2) they don't have doorlock mechanisms.
> * This test catches them, and is invoked elsewhere when setting appropriate
> * config bits.
> *
> */
>
> Since hda in my system is a CompactFlash card I began to look further and then with some
> discovered the following in ide-probe.c
>
> /*
> * Prevent long system lockup probing later for non-existant
> * slave drive if the hwif is actually a flash memory card of some variety:
> */
> if (drive_is_flashcard(drive)) {
> ide_drive_t *mate = &HWIF(drive)->drives[1^drive->select.b.unit];
> if (!mate->ata_flash) {
> mate->present = 0;
> ide_drive_t *mate = &HWIF(drive)->drives[1^drive->select.b.unit]
> mate->noprobe = 1;
> }
> }
>
> Now perhaps I am just way out on the wacky edge of things but I don't agree with the
> above in the slightest. We use CF's in conjunction with slaves all the time. Almost all
> of our embedded devices boot from CF's and I routinely add a HD as a slave to the system
> to do developement with but it's always been under DOS.
>
> I comment out the check above and all is well... hdb shows up as expected.
>
> Can someone explain to me why the above check was added and if its continued existence is
> necessary? Whats this long system lockup thing mentioned?
>
> Even if there is some danger of a long lockup I suggest that at least a message that its
> ignoring hdb is the least it could do rather than sliently ignoreing it. Especially when
> I specifically told it a hdb existed via the command line. Shouldn't command line
> parameters take precidence?
>
> I not subscribed to the kernel-list so please copy me in the response.
>
> Thanks.
>
>
> --
> Richard A. Smith ras2@tant.com
> "I'd hang out with science kids - they can blow things up!
> I mean, what's cooler than that?"
> - Tori Amos
>
>
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