diff options
Diffstat (limited to 'drivers/ata/libata-core.c')
| -rw-r--r-- | drivers/ata/libata-core.c | 59 |
1 files changed, 32 insertions, 27 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 09ed67772fae..be3412cdb22e 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2001,6 +2001,33 @@ bool ata_dev_power_init_tf(struct ata_device *dev, struct ata_taskfile *tf, return true; } +static bool ata_dev_power_is_active(struct ata_device *dev) +{ + struct ata_taskfile tf; + unsigned int err_mask; + + ata_tf_init(dev, &tf); + tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR; + tf.protocol = ATA_PROT_NODATA; + tf.command = ATA_CMD_CHK_POWER; + + err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0); + if (err_mask) { + ata_dev_err(dev, "Check power mode failed (err_mask=0x%x)\n", + err_mask); + /* + * Assume we are in standby mode so that we always force a + * spinup in ata_dev_power_set_active(). + */ + return false; + } + + ata_dev_dbg(dev, "Power mode: 0x%02x\n", tf.nsect); + + /* Active or idle */ + return tf.nsect == 0xff; +} + /** * ata_dev_power_set_standby - Set a device power mode to standby * @dev: target device @@ -2017,6 +2044,11 @@ void ata_dev_power_set_standby(struct ata_device *dev) struct ata_taskfile tf; unsigned int err_mask; + /* If the device is already sleeping or in standby, do nothing. */ + if ((dev->flags & ATA_DFLAG_SLEEPING) || + !ata_dev_power_is_active(dev)) + return; + /* * Some odd clown BIOSes issue spindown on power off (ACPI S4 or S5) * causing some drives to spin up and down again. For these, do nothing @@ -2042,33 +2074,6 @@ void ata_dev_power_set_standby(struct ata_device *dev) err_mask); } -static bool ata_dev_power_is_active(struct ata_device *dev) -{ - struct ata_taskfile tf; - unsigned int err_mask; - - ata_tf_init(dev, &tf); - tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR; - tf.protocol = ATA_PROT_NODATA; - tf.command = ATA_CMD_CHK_POWER; - - err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0); - if (err_mask) { - ata_dev_err(dev, "Check power mode failed (err_mask=0x%x)\n", - err_mask); - /* - * Assume we are in standby mode so that we always force a - * spinup in ata_dev_power_set_active(). - */ - return false; - } - - ata_dev_dbg(dev, "Power mode: 0x%02x\n", tf.nsect); - - /* Active or idle */ - return tf.nsect == 0xff; -} - /** * ata_dev_power_set_active - Set a device power mode to active * @dev: target device |