Re: Hacking ide.c for better pcmcia support...

Mark Lord (mlord@pobox.com)
Mon, 16 Nov 1998 18:12:38 +0000

Colin Plumb wrote:
..
> The problem is that if something ends up holding the mount open, then
> ide_unregister fails, and since it returns void, the failure goes unreported
> and the kernel ends up stuck in a bad state.
>
> The lack of umount -f is certainly a problem, but I'd also like unregister_ide
> to *do* something sensible if the device is busy.

Yeah, I noticed that too, but it is a user-bug, not a kernel-bug.

Nicer behaviour for PCMCIA CompactFlash-ATA devices would be
a useful thing for 2.3.xx. There is a CODE FREEZE on 2.1.xxx now.

The required solution is to parameterize the internal IDE timeouts
on a per-drive basis. That way, the pcmcia utilities could set the
timeouts to zero for CompactFlash-ATA-flash cards, but use different
values for CompactFlash-ATA-disk cards (like the IBM 230MB thingie).

With tiny timeouts for true flash memory, the zombie requests would
die rather rapidly, unlike today.

> One question: in the ide_drive_t structure, there are already 16 bits
> allocated in the bit-field range. (If FAKE_FDISK_FOR_EZDRIVE is
> set.) Should I just add another flag there? Is there a reason why
> the booleans before that are bytes and not bits?

The more frequently-accessed bools are bytes for faster-access,
the rest are bits to save memory. I was frugal about memory
at one time.. :)

-- 
mlord@pobox.com


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