Merge v7.2.5linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 58f512f8952a..9b8c0935001c 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -2614,6 +2614,51 @@ static irqreturn_t ahci_thunderx_irq_handler(int irq, void *dev_instance)
 }
 #endif
 
+/*
+ * The Marvell 88SE6111/6121/6145 ("Thor") family stops reporting interrupts
+ * for a port when HOST_IRQ_STAT is cleared while PxIS still holds bits: PxIS
+ * keeps its content, HOST_IRQ_STAT reads back as 0, the port is never looked
+ * at again and the command in flight only ends in a timeout.  On a 88SE6121
+ * this makes every SATA-2 or SATA-3 disk fail to IDENTIFY, while SATA-1 disks
+ * happen to win the race often enough to work.
+ *
+ * Clearing the host status before servicing the ports avoids it.  Marvell's
+ * own driver for these chips does the same and says so ("clear global before
+ * channel"), and ahci_xgene handles its broken edge latch the same way.  The
+ * price is at most one spurious interrupt per valid one, which is why this is
+ * not the generic behaviour - see AHCI 1.1 section 10.6.2.
+ *
+ * Link: https://bugzilla.kernel.org/show_bug.cgi?id=216094
+ */
+static irqreturn_t ahci_mv_irq_handler(int irq, void *dev_instance)
+{
+	struct ata_host *host = dev_instance;
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	unsigned int rc;
+	u32 irq_stat, irq_masked;
+
+	irq_stat = readl(mmio + HOST_IRQ_STAT);
+	if (!irq_stat)
+		return IRQ_NONE;
+
+	irq_masked = irq_stat & hpriv->port_map;
+
+	spin_lock(&host->lock);
+
+	/*
+	 * Use the unmasked value to clear the interrupt, as a spurious pending
+	 * event on a dummy port might cause a screaming IRQ.
+	 */
+	writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+	rc = ahci_handle_port_intr(host, irq_masked);
+
+	spin_unlock(&host->lock);
+
+	return IRQ_RETVAL(rc);
+}
+
 static void ahci_remap_check(struct pci_dev *pdev, int bar,
 		struct ahci_host_priv *hpriv)
 {
@@ -2917,6 +2962,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return -ENOMEM;
 	hpriv->flags |= (unsigned long)pi.private_data;
 
+	/* the Marvell "Thor" family needs HOST_IRQ_STAT cleared first */
+	if (board_id == board_ahci_mv)
+		hpriv->irq_handler = ahci_mv_irq_handler;
+
 	/* MCP65 revision A1 and A2 can't do MSI */
 	if (board_id == board_ahci_mcp65 &&
 	    (pdev->revision == 0xa1 || pdev->revision == 0xa2))