| commit | 96d60303fd3336893a93565d58c4f1805a327061 | [log] [tgz] |
|---|---|---|
| author | Matthew Garrett <mjg@redhat.com> | Sun Mar 28 00:37:21 2010 -0400 |
| committer | Jeff Garzik <jgarzik@redhat.com> | Fri May 14 17:08:01 2010 -0400 |
| tree | e6534dabeceb4a0a0b511c17dbffe47639fff0ac | |
| parent | 1c2a49f61785ebbcbfb481a2aab659020f0457f7 [diff] |
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>