[PATCH v3 1/2] libahci: Implement the function ahci_restart_engine to restart the port dma engine.

[Suman Tripathi <stripathi@apm.com>]

This patch adds an function to restart the port dma engine.

Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
 drivers/ata/ahci.h    |  1 +
 drivers/ata/libahci.c | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index af63c75..3c1760e 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -372,6 +372,7 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,

 int ahci_stop_engine(struct ata_port *ap);
 void ahci_start_engine(struct ata_port *ap);
+int ahci_restart_engine(struct ata_port *ap);
 int ahci_check_ready(struct ata_link *link);
 int ahci_kick_engine(struct ata_port *ap);
 int ahci_port_resume(struct ata_port *ap);
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index b986145..d1c9122 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -742,6 +742,18 @@ static int ahci_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 	return 0;
 }

+int ahci_restart_engine(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+
+	ahci_stop_engine(ap);
+	ahci_start_fis_rx(ap);
+	hpriv->start_engine(ap);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_restart_engine);
+
 #ifdef CONFIG_PM
 static void ahci_power_down(struct ata_port *ap)
 {
--
1.8.2.1