On Sunday, 14 of September 2008, Jeff Garzik wrote:
quoted text
> Tejun Heo wrote:
> > Rafael J. Wysocki wrote:
> >> SATA: Blacklist systems that spin off disks during ACPI power off
> >>
> >> Some notebooks from HP have the problem that their BIOSes attempt to
> >> spin down hard drives before entering ACPI system states S4 and S5.
> >> This leads to a yo-yo effect during system power-off shutdown and the
> >> last phase of hibernation when the disk is first spun down by the
> >> kernel and then almost immediately turned on and off by the BIOS.
> >> This, in turn, may result in shortening the disk's life times.
> >>
> >> To prevent this from happening we can blacklist the affected systems
> >> using DMI information.  However, only the on-board controlles should
> >> be blacklisted and their PCI slot numbers can be used for this
> >> purpose.  Unfortunately the existing interface for checking DMI
> >> information of the system is not very convenient for this purpose,
> >> because to use it, we would have to define special callback functions
> >> or create a separate struct dmi_system_id table for each blacklisted
> >> system.
> >>
> >> To overcome this difficulty introduce a new function
> >> dmi_first_match() returning a pointer to the first entry in an array
> >> of struct dmi_system_id elements that matches the system DMI
> >> information.  Then, we can use this pointer to access the entry's
> >> .driver_data field containing the additional information, such as
> >> the PCI slot number, allowing us to do the desired blacklisting.
> >>
> >> Introduce a new libata flag ATA_FLAG_NO_POWEROFF_SPINDOWN that, if
> >> set, will prevent disks from being spun off during system power off
> >> and hibernation (to handle the hibernation case we need a new system
> >> state SYSTEM_HIBERNATE_ENTER that can be checked against by libata,
> >> in analogy with SYSTEM_POWER_OFF).  Use dmi_first_match() to set this
> >> flag for some systems affected by the problem described above (HP nx6325,
> >> HP nx6310, HP 2510p).
> >>
> >> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > libata part looks good to me but I think it would be better to
> > separate out DMI changes into a separate patch.
> 
> Did these changes ever get separated out?

I only have the 'combo' patch if that's what you're asking about.  [The latest
version is at http://bugzilla.kernel.org/attachment.cgi?id=17702&action=view]

Still, I can easily split the patch, although in that case the reason for the
DMI changes won't be very clear without a reference to the SATA changes IMO.

Thanks,
Rafael
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