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authorMatthew Garrett <mjg@redhat.com>2010-03-28 00:37:21 -0400
committerJeff Garzik <jgarzik@redhat.com>2010-05-14 17:08:01 -0400
commit96d60303fd3336893a93565d58c4f1805a327061 (patch)
treee6534dabeceb4a0a0b511c17dbffe47639fff0ac /drivers/ata/ahci.c
parent1c2a49f61785ebbcbfb481a2aab659020f0457f7 (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>
Diffstat (limited to 'drivers/ata/ahci.c')
0 files changed, 0 insertions, 0 deletions