[PATCH v2] ahci: libahci: clear pending interrupt status

[Szuying Chen]

This patch adds the function to clear pending interrupt before COMRESET.
It follows the  AHCI1.3.1 - section6.2.2.2 specification.

Signed-off-by: Szuying Chen <Chloe_Chen@xxxxxxxxxxxxxx>
---modify function name and substitution related behavior.

 drivers/ata/libahci.c | 38 ++++++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 06aec35f88f2..f8ecd9956ea1 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1256,6 +1256,27 @@ static ssize_t ahci_activity_show(struct ata_device *dev, char *buf)
 	return sprintf(buf, "%d\n", emp->blink_policy);
 }

+static void ahci_port_clear_pending_irq(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 tmp;
+
+	/* clear SError */
+	tmp = readl(port_mmio + PORT_SCR_ERR);
+	dev_dbg(ap->host->dev, "PORT_SCR_ERR 0x%x\n", tmp);
+	writel(tmp, port_mmio + PORT_SCR_ERR);
+
+	/* clear port IRQ */
+	tmp = readl(port_mmio + PORT_IRQ_STAT);
+	dev_dbg(ap->host->dev, "PORT_IRQ_STAT 0x%x\n", tmp);
+	if (tmp)
+		writel(tmp, port_mmio + PORT_IRQ_STAT);
+
+	writel(1 << ap->port_no, hpriv->mmio + HOST_IRQ_STAT);
+
+}
+
 static void ahci_port_init(struct device *dev, struct ata_port *ap,
 			   int port_no, void __iomem *mmio,
 			   void __iomem *port_mmio)
@@ -1270,18 +1291,8 @@ static void ahci_port_init(struct device *dev, struct ata_port *ap,
 	if (rc)
 		dev_warn(dev, "%s (%d)\n", emsg, rc);

-	/* clear SError */
-	tmp = readl(port_mmio + PORT_SCR_ERR);
-	dev_dbg(dev, "PORT_SCR_ERR 0x%x\n", tmp);
-	writel(tmp, port_mmio + PORT_SCR_ERR);
-
-	/* clear port IRQ */
-	tmp = readl(port_mmio + PORT_IRQ_STAT);
-	dev_dbg(dev, "PORT_IRQ_STAT 0x%x\n", tmp);
-	if (tmp)
-		writel(tmp, port_mmio + PORT_IRQ_STAT);
-
-	writel(1 << port_no, mmio + HOST_IRQ_STAT);
+	/* clear pending irq */
+	ahci_port_clear_pending_irq(ap);

 	/* mark esata ports */
 	tmp = readl(port_mmio + PORT_CMD);
@@ -1602,6 +1613,9 @@ int ahci_do_hardreset(struct ata_link *link, unsigned int *class,
 	tf.status = ATA_BUSY;
 	ata_tf_to_fis(&tf, 0, 0, d2h_fis);

+	/* clear pending irq */
+	ahci_port_clear_pending_irq(ap);
+
 	rc = sata_link_hardreset(link, timing, deadline, online,
 				 ahci_check_ready);

--
2.39.2