[Pm-utils] Quirk for running hdparm after resume from suspend and hibernate

[Dan Nicholson]

On Thu, Jan 29, 2009 at 7:36 AM, Pedro R <eusou15 at yahoo.com> wrote:
> Sorry for coming into the discussion like this, but i joined this mailing list because of exactly the same problem.
>
> This hdparm issue is distro specific, i'm sure hdparm upstream will not want to handle it, because honestly they don't have to. Fixing it in pm-utils is pernicious, because this issue only affects laptops, but i still think it's the best way.
>
> This is a major issue going on since 2005 and nobody seems to want to get their hands dirty fixing it. It would be great to include this in pm-utils, since the collateral overhead for desktop computers is not that big either.
>
> Anyway the hook should be executed on resume (but not on hibernate / standby) and on power change: battery -> ac adaptor and ac adaptor -> battery, because when on battery the setting should be -B 128 (because of physical shocks - for an explanation refer to the load_cycle_count issue on google) and on ac power it should be -B 254. To do this, the hook should not rely on other than the kernel itself. Like this:
>
>        if cat /proc/acpi/ac_adapter/ACAD/state | grep 'off-line' ; then
>          hdparm -B 128 $dev
>        else
>          hdparm -B 254 $dev

But the AC adaptor state has nothing to do with suspending. If you
really wanted to do this, wouldn't it be better to have a service
listen to AC adaptor events on HAL?

Back to the more general issue, why does the drive drop the Advanced
Power Management setting when suspending? This really sounds like a
kernel bug to me. This is exactly the type of state that should be
saved by the driver to be restored when resuming.

--
Dan