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SubjectQuestion about IDE disk shutdown

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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