Link power management is about to be reimplemented. Prepare for it.
* Implement sata_link_scr_lpm().
* Drop static from ata_dev_set_feature() and make it available to
other libata files.
* Trivial whitespace adjustments.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
drivers/ata/libata-core.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
drivers/ata/libata.h | 2 +
include/linux/libata.h | 2 +
3 files changed, 74 insertions(+), 5 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index a7274f5..c8573e0 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -91,8 +91,6 @@ const struct ata_port_operations sata_port_ops = {
static unsigned int ata_dev_init_params(struct ata_device *dev,
u16 heads, u16 sectors);
static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
-static unsigned int ata_dev_set_feature(struct ata_device *dev,
- u8 enable, u8 feature);
static void ata_dev_xfermask(struct ata_device *dev);
static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
@@ -3628,7 +3626,7 @@ int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
* @params: timing parameters { interval, duratinon, timeout } in msec
* @deadline: deadline jiffies for the operation
*
-* Make sure SStatus of @link reaches stable state, determined by
+ * Make sure SStatus of @link reaches stable state, determined by
* holding the same value where DET is not 1 for @duration polled
* every @interval, before @timeout. Timeout constraints the
* beginning of the stable state. Because DET gets stuck at 1 on
@@ -3760,6 +3758,72 @@ int sata_link_resume(struct ata_link *link, const unsigned long *params,
}
/**
+ * sata_link_scr_lpm - manipulate SControl IPM and SPM fields
+ * @link: ATA link to manipulate SControl for
+ * @policy: LPM policy to configure
+ * @spm_wakeup: initiate LPM transition to active state
+ *
+ * Manipulate the IPM field of the SControl register of @link
+ * according to @policy. If @policy is ATA_LPM_MAX_POWER and
+ * @spm_wakeup is %true, the SPM field is manipulated to wake up
+ * the link. This function also clears PHYRDY_CHG before
+ * returning.
+ *
+ * LOCKING:
+ * EH context.
+ *
+ * RETURNS:
+ * 0 on succes, -errno otherwise.
+ */
+int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+ bool spm_wakeup)
+{
+ struct ata_eh_context *ehc = &link->eh_context;
+ bool woken_up = false;
+ u32 scontrol;
+ int rc;
+
+ rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
+ if (rc)
+ return rc;
+
+ switch (policy) {
+ case ATA_LPM_MAX_POWER:
+ /* disable all LPM transitions */
+ scontrol |= (0x3 << 8);
+ /* initiate transition to active state */
+ if (spm_wakeup) {
+ scontrol |= (0x4 << 12);
+ woken_up = true;
+ }
+ break;
+ case ATA_LPM_MED_POWER:
+ /* allow LPM to PARTIAL */
+ scontrol &= ~(0x1 << 8);
+ scontrol |= (0x2 << 8);
+ break;
+ case ATA_LPM_MIN_POWER:
+ /* no restrictions on LPM transitions */
+ scontrol &= ~(0x3 << 8);
+ break;
+ default:
+ WARN_ON(1);
+ }
+
+ rc = sata_scr_write(link, SCR_CONTROL, scontrol);
+ if (rc)
+ return rc;
+
+ /* give the link time to transit out of LPM state */
+ if (woken_up)
+ msleep(10);
+
+ /* clear PHYRDY_CHG from SError */
+ ehc->i.serror &= ~SERR_PHYRDY_CHG;
+ return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
+}
+
+/**
* ata_std_prereset - prepare for reset
* @link: ATA link to be reset
* @deadline: deadline jiffies for the operation
@@ -4551,6 +4615,7 @@ static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
DPRINTK("EXIT, err_mask=%x\n", err_mask);
return err_mask;
}
+
/**
* ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
* @dev: Device to which command will be sent
@@ -4566,8 +4631,7 @@ static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
* RETURNS:
* 0 on success, AC_ERR_* mask otherwise.
*/
-static unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable,
- u8 feature)
+unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable, u8 feature)
{
struct ata_taskfile tf;
unsigned int err_mask;
@@ -6720,6 +6784,7 @@ EXPORT_SYMBOL_GPL(sata_set_spd);
EXPORT_SYMBOL_GPL(ata_wait_after_reset);
EXPORT_SYMBOL_GPL(sata_link_debounce);
EXPORT_SYMBOL_GPL(sata_link_resume);
+EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
EXPORT_SYMBOL_GPL(ata_std_prereset);
EXPORT_SYMBOL_GPL(sata_link_hardreset);
EXPORT_SYMBOL_GPL(sata_std_hardreset);
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 1471462..65b6a73 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -86,6 +86,8 @@ extern int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
extern int ata_dev_configure(struct ata_device *dev);
extern int sata_down_spd_limit(struct ata_link *link, u32 spd_limit);
extern int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel);
+extern unsigned int ata_dev_set_feature(struct ata_device *dev,
+ u8 enable, u8 feature);
extern void ata_sg_clean(struct ata_queued_cmd *qc);
extern void ata_qc_free(struct ata_queued_cmd *qc);
extern void ata_qc_issue(struct ata_queued_cmd *qc);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index acfb650..da71bb9 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -950,6 +950,8 @@ extern int sata_link_debounce(struct ata_link *link,
const unsigned long *params, unsigned long deadline);
extern int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline);
+extern int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+ bool spm_wakeup);
extern int sata_link_hardreset(struct ata_link *link,
const unsigned long *timing, unsigned long deadline,
bool *online, int (*check_ready)(struct ata_link *));
--
1.7.1
--
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