Re: How to quickly detect the mode change of a hard disk?

From: Hui Cheng
Date: Fri Nov 18 2005 - 14:41:26 EST

On Wed, 16 Nov 2005, Alejandro Bonilla wrote:

> On Sun, 13 Nov 2005 15:10:56 +0000, Pavel Machek wrote
> > > I am currently doing a kernel module involves detecting/changing
> > > disk mode among STANDBY and ACTIVE/IDLE. I used ide_cmd_wait() to issue
> > > commands like WIN_IDLEIMMEDIATELY and WIN_STANDBYNOW1. The problem is, a
> > > drive in standby mode will automatically awake whenever a disk operation
> > > is requested and I need to know the mode change as soon as possible. (So I
> >
> > AFAIK there's no nice way to get that info, but it is useful, so
> > patch would be welcome.
> I would check the hdparm man page again. Still, it sounds interesting.
> Additionally, it could be cool if someone could finish up or make the option
> for the HD freeze to use it with the HDAPS driver. ;-)
> .Alejandro

Thanks for reply :) What I did to handle this problem is a little stupid
: Suppose the disk is now in a standby mode. In case that there is a
request sent to the disk drive, a kernel thread is awake to detect/update
the current disk power mode. The disk power mode is stored in the
ide_drive_t structure and be protected by lock. It seems to work fine in
my simple tests. But again, there should be better solutions.


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