[PATCH 1/2] ahci: Add PhyRdy Change control on actual LPM capability

[Runa Guo-oc <RunaGuo-oc@zhaoxin.com>]

On some platform, when OS enables LPM by default (eg, min_power),
then, PhyRdy Change cannot be detected if ahci supports no LPM.

In ahci spec, PhyRdy Change cannot coexist with LPM.

Adds support to control this case on actual LPM capability.

Signed-off-by: Runa Guo-oc <RunaGuo-oc@zhaoxin.com>
---
 drivers/ata/ahci.c      | 9 +++++++++
 drivers/ata/libata-eh.c | 4 ++++
 include/linux/libata.h  | 4 ++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 397dfd2..03f0cb3 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1870,6 +1870,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	else
 		dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
 
+	if (hpriv->cap & HOST_CAP_PART)
+		host->flags |= ATA_HOST_PART;
+
+	if (hpriv->cap & HOST_CAP_SSC)
+		host->flags |= ATA_HOST_SSC;
+
+	if (hpriv->cap2 & HOST_CAP2_SDS)
+		host->flags |= ATA_HOST_DEVSLP;
+
 	if (pi.flags & ATA_FLAG_EM)
 		ahci_reset_em(host);
 
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 3307ed4..05b1043 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3246,6 +3246,10 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 	unsigned int err_mask;
 	int rc;
 
+	/* if controller does not support lpm, then sets no LPM flags*/
+	if (!(ap->host->flags & (ATA_HOST_PART | ATA_HOST_SSC | ATA_HOST_DEVSLP)))
+		link->flags |= ATA_LFLAG_NO_LPM;
+
 	/* if the link or host doesn't do LPM, noop */
 	if (!IS_ENABLED(CONFIG_SATA_HOST) ||
 	    (link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 732de90..7a243f4 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -216,6 +216,10 @@ enum {
 	ATA_HOST_PARALLEL_SCAN	= (1 << 2),	/* Ports on this host can be scanned in parallel */
 	ATA_HOST_IGNORE_ATA	= (1 << 3),	/* Ignore ATA devices on this host. */
 
+	ATA_HOST_PART		= (1 << 4), /* Host support partial.*/
+	ATA_HOST_SSC		= (1 << 5), /* Host support slumber.*/
+	ATA_HOST_DEVSLP		= (1 << 6), /* Host support devslp.*/
+
 	/* bits 24:31 of host->flags are reserved for LLD specific flags */
 
 	/* various lengths of time */
-- 
2.7.4