[PATCH v3] ahci: libahci: clear pending interrupt status

[Szuying Chen]

Cleared PxIS and PxIE with error recovery when ISR handle interface fatal.
Then a SDB FIS with ERR (set PxIS.TFES) is received
before PxCMD.ST is set to 0.
When error recovery was finish and PxCMD.ST is set to 1.
The HBA can't issue any new commands.
Because the PxIS.TFES bit is not cleared.
To avoid this,
we adds the function to clear pending interrupt before COMRESET.
It follows the AHCI 1.3.1 - section 6.2.2.2 specification.

Signed-off-by: Szuying Chen <Chloe_Chen@xxxxxxxxxxxxxx>
---
V1->V2: On suggestion by Damien to renamed helper function and modified
ahci_port_init() to make use of the helper.
V2->V3: On suggestion by Niklas to modify commit log and delete the
extra describe.

 drivers/ata/libahci.c | 35 +++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index e2bacedf28ef..f1263364fa97 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1256,6 +1256,26 @@ 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 +1290,7 @@ 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);
+	ahci_port_clear_pending_irq(ap);

 	/* mark esata ports */
 	tmp = readl(port_mmio + PORT_CMD);
@@ -1603,6 +1612,8 @@ int ahci_do_hardreset(struct ata_link *link, unsigned int *class,
 	tf.status = ATA_BUSY;
 	ata_tf_to_fis(&tf, 0, 0, d2h_fis);

+	ahci_port_clear_pending_irq(ap);
+
 	rc = sata_link_hardreset(link, timing, deadline, online,
 				 ahci_check_ready);

--
2.39.2