In message <20040523004211.GA18223@drowsy.duskware.de>, Martin Husemann writes:
>On Sun, May 23, 2004 at 08:10:00AM +0900, ITOH Yasufumi wrote:
>
>> I think the problem is that the pcmcia/cardbus driver turns
>> on and off the device too frequently during probe/attach (kern/8731).
>
>It's been a while, but last I looked there was one power up-probe-power-down
>phase, optionally followed by another power-up-on-mount. I don't see how you
>could optimize that.
>
>> I think we can fix both problems by delaying power down for a while
>> (say 5s) after power-down requests.
>
>There is a final flush command to the drive before power is turned off,
>so this should not be needed - IIUC.
>

As I noted, *something* didn't work right if the device was powered 
down too fast after an unmount.

I can confirm that there are lots of power up/power down cycles trying 
to mount a PCMCIA IDE disk.  *Lots* of experience this weekend, I 
fear...  (Using 'dkctl setcache r' seemed to help, but I'm not certain 
it was 100% effective.  It isn't clear to me when I have to issue that. 
Once per card insertion?  Once per power-up, i.e., mount or fdisk?)


		--Steve Bellovin, http://www.research.att.com/~smb