diff options
| author | Kristen Carlson Accardi <kristen@linux.intel.com> | 2011-03-04 10:24:11 -0800 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@pobox.com> | 2011-05-19 20:50:53 -0400 |
| commit | 8a745f1f39b7a20047a362b67ce9151c07d14440 (patch) | |
| tree | f8f08be7a284d195f30a8b2e6fc63b714e4f7f21 | |
| parent | 0afc6f5ba95419fd505e60637f7645425f16e407 (diff) | |
| download | lwn-8a745f1f39b7a20047a362b67ce9151c07d14440.tar.gz lwn-8a745f1f39b7a20047a362b67ce9151c07d14440.zip | |
libata: Power off empty ports
Give users the option of completely powering off unoccupied
SATA ports using the existing min_power link_power_management_policy
option. When the use selects this option on an empty port, we
will power the port off by setting DET to off. For occupied ports,
behavior is unchanged.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
| -rw-r--r-- | drivers/ata/libata-core.c | 10 | ||||
| -rw-r--r-- | drivers/ata/libata-eh.c | 2 | ||||
| -rw-r--r-- | include/linux/libata.h | 1 |
3 files changed, 10 insertions, 3 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 76c3c15cb1e6..736bee5dafeb 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -3619,8 +3619,14 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy, scontrol |= (0x2 << 8); break; case ATA_LPM_MIN_POWER: - /* no restrictions on LPM transitions */ - scontrol &= ~(0x3 << 8); + if (ata_link_nr_enabled(link) > 0) + /* no restrictions on LPM transitions */ + scontrol &= ~(0x3 << 8); + else { + /* empty port, power off */ + scontrol &= ~0xf; + scontrol |= (0x1 << 2); + } break; default: WARN_ON(1); diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index dad9fd660f37..dfb6e9d3d759 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -3423,7 +3423,7 @@ fail: return rc; } -static int ata_link_nr_enabled(struct ata_link *link) +int ata_link_nr_enabled(struct ata_link *link) { struct ata_device *dev; int cnt = 0; diff --git a/include/linux/libata.h b/include/linux/libata.h index 04f32a3eb26b..5a9926b34072 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1151,6 +1151,7 @@ extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset, ata_reset_fn_t softreset, ata_reset_fn_t hardreset, ata_postreset_fn_t postreset); extern void ata_std_error_handler(struct ata_port *ap); +extern int ata_link_nr_enabled(struct ata_link *link); /* * Base operations to inherit from and initializers for sht |