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| author | Matthew Garrett <mjg@redhat.com> | 2010-03-28 00:37:21 -0400 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2010-05-14 17:08:01 -0400 |
| commit | 96d60303fd3336893a93565d58c4f1805a327061 (patch) | |
| tree | e6534dabeceb4a0a0b511c17dbffe47639fff0ac /drivers/ata/ahci.h | |
| parent | 1c2a49f61785ebbcbfb481a2aab659020f0457f7 (diff) | |
| download | linux-3.10-96d60303fd3336893a93565d58c4f1805a327061.tar.gz linux-3.10-96d60303fd3336893a93565d58c4f1805a327061.tar.bz2 linux-3.10-96d60303fd3336893a93565d58c4f1805a327061.zip | |
ahci: Turn off DMA engines when there's no device attached
According to section 10.3.1 of the AHCI spec, PxCMD.ST must not be set
unless there's a device attached. Following this saves us a measurable
quantity of power and does not impair hotplug support. Based on a patch
by Kristen Carlson Accardi.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/ahci.h')
0 files changed, 0 insertions, 0 deletions