Subject: Re: accessing IDE hard drive via pcmcia card (redirected from netbsd-users)
To: None <>
From: ITOH Yasufumi <>
List: tech-kern
Date: 05/23/2004 13:35:10 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 have 1.6ZL (May 27, 2004) kernel, and I see at least two power on/off
cycles while probe and attach.

	power ON
	read CIS
	power OFF
	power ON
	attach wdc
	power OFF

If we keeps power all the time, we will have more time to stabilize
the device.

> > 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.

The power-off delay is one method to avoid excessive power on-off cycles,
which might help for data integrity but is not required of course.
ITOH Yasufumi