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@xxxxxxx> libata part looks good to me but I think it would be better to separate out DMI changes into a separate patch. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
