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    SubjectQuestion about IDE disk shutdown
    Date

    Hello all,

    Probably a trivial question for ones who know it - what IDE commands does
    kernel issue when shutting down (which results in automatic power-off if ACPI
    is enabled)?

    According to my hard disk manual, it is absolutely recommended to put the
    drive in STANDBY or SLEEP mode before power cut-off because in that way heads
    are nicely parked. In that way it is guaranteed to have 300000 head
    load/unload cycles minimum, while in other case it is just 20000 cycles.

    It also explicitely states that FLUSH CACHE is not to be used for drive
    power-off because it does not park the heads.

    Looking at the source I see in ide-disk.c:

    .gen_driver = {
    .shutdown = ide_device_shutdown,
    },

    Following that I see that ide_device_shutdown flushes the cache, and then
    calls dev->bus->suspend(dev, PM_SUSPEND_STANDBY); which is in fact
    generic_ide_suspend, right? There, something called REQ_PM_SUSPEND is issued
    to the drive. As SUSPEND != STANDBY or SLEEP, I am left uncertain.

    Is there a place to be worried or I am missing something?
    -
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