From: "Jeffrey W. Baker" <jwbaker@gmail.com>
To: linux-ide@vger.kernel.org
Subject: AHCI power down unused ports merge status?
Date: Sat, 27 Sep 2008 12:39:15 -0700 [thread overview]
Message-ID: <1222544355.26413.6.camel@stinklet> (raw)
I was just poking around in the ICH8 documentation and /dev/mem and I
notice that all three of the SATA PHYs on my laptop are enabled, when I
have only one SATA target device. AHCI allows the port to be disabled,
and this saves a lot of power, but this functionality is not exposed in
Linux.
There are patches floating around on this mailing list to disable the
port by echoing "power_off" to ALPM in sysfs, but this patch isn't
merged in libata-dev and I don't see it in 2.6.27-rc7 either. Is there
any hope of this getting merged? Is it dangerous or otherwise not
advised?
I think users would really appreciate having this. Disabling unused
ports results in +10% extra battery life on my laptop.
cf http://marc.info/?l=linux-ide&m=121504056904748&w=2
I think part 1 is severable from part 2, so perhaps the sysfs bits can
be merged without the default policy part that seems objectionable.
-jwb
reply other threads:[~2008-09-27 19:39 UTC|newest]
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