lkml.org 
[lkml]   [2004]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
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?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:03    [from the cache]
©2003-2011 Jasper Spaans