From 8a745f1f39b7a20047a362b67ce9151c07d14440 Mon Sep 17 00:00:00 2001 From: Kristen Carlson Accardi Date: Fri, 4 Mar 2011 10:24:11 -0800 Subject: [PATCH] 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 Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 10 ++++++++-- drivers/ata/libata-eh.c | 2 +- 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 76c3c15..736bee5 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 dad9fd6..dfb6e9d 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 04f32a3..5a9926b 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 -- 2.7.4