Subject: Re: accessing IDE hard drive via pcmcia card (redirected from netbsd-users)
To: Martin Husemann <firstname.lastname@example.org>
From: Steven M. Bellovin <email@example.com>
Date: 05/23/2004 18:22:08
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