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@xxxxxxxxxxxxxxx>
---
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 d4e52e2..a650bef 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 17a6378..f0a31b7 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3381,7 +3381,7 @@ 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 c9c5d7a..8e78052 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1155,6 +1155,7 @@ 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
--
1.7.3.1
--
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