From: Tirumalesh Chalamarla <tchalamarla@xxxxxxxxxxxxxxxxxx>
Due to Errata in some versions of ThunderX,
HOST_IRQ_STAT is neither EDGE nor LEVEL,
ThunderX needs a special sequence for handling interrupt.
The patch attempts to satisfy the need.
Signed-off-by: Tirumalesh Chalamarla <tchalamarla@xxxxxxxxxxxxxxxxxx>
---
drivers/ata/ahci.c | 3 +++
drivers/ata/ahci.h | 4 ++++
drivers/ata/libahci.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 59 insertions(+)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 594fcab..6416af7 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1534,6 +1534,9 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
if (ahci_sb600_enable_64bit(pdev))
hpriv->flags &= ~AHCI_HFLAG_32BIT_ONLY;
+ if (pdev->vendor == 0x177d && pdev->device == 0xa01c)
+ hpriv->flags |= AHCI_HFLAG_CAVIUM_ERRATA_22536;
+
hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar];
/* must set flag prior to save config in order to take effect */
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index a44c75d..50b2afd 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -252,6 +252,10 @@ enum {
#endif
AHCI_HFLAG_WAKE_BEFORE_STOP = (1 << 22), /* wake before DMA stop */
+ AHCI_HFLAG_CAVIUM_ERRATA_22536 = (1 << 23), /* Thunder HOST_IRQ_STAT
+ * is not Level or EDGE
+ */
+
/* ap->flags bits */
AHCI_FLAG_COMMON = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA |
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 4029679..e186482 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1952,6 +1952,55 @@ static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance)
return IRQ_RETVAL(rc);
}
+
+static irqreturn_t ahci_level_irq_with_errata(int irq, void *dev_instance)
+{
+ struct ata_host *host = dev_instance;
+ struct ahci_host_priv *hpriv;
+ unsigned int rc = 0;
+ void __iomem *mmio;
+ u32 irq_stat, irq_masked;
+ unsigned int handled = 1;
+
+ VPRINTK("ENTER\n");
+
+ hpriv = host->private_data;
+ mmio = hpriv->mmio;
+
+ /* sigh. 0xffffffff is a valid return from h/w */
+ irq_stat = readl(mmio + HOST_IRQ_STAT);
+ if (!irq_stat)
+ return IRQ_NONE;
+redo:
+
+ irq_masked = irq_stat & hpriv->port_map;
+
+ spin_lock(&host->lock);
+
+ rc = ahci_handle_port_intr(host, irq_masked);
+
+ if (!rc)
+ handled = 0;
+
+ writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+ /* Due to ERRATA#22536, ThunderX need to handle
+ * HOST_IRQ_STAT differently.
+ * Work around is to make sure all pending IRQs
+ * are served before leaving handler
+ */
+ irq_stat = readl(mmio + HOST_IRQ_STAT);
+
+ spin_unlock(&host->lock);
+
+ if (irq_stat)
+ goto redo;
+
+ VPRINTK("EXIT\n");
+
+ return IRQ_RETVAL(handled);
+}
+
unsigned int ahci_qc_issue(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
@@ -2540,6 +2589,9 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
else if (hpriv->flags & AHCI_HFLAG_EDGE_IRQ)
rc = ata_host_activate(host, irq, ahci_single_edge_irq_intr,
IRQF_SHARED, sht);
+ else if (hpriv->flags & AHCI_HFLAG_CAVIUM_ERRATA_22536)
+ rc = ata_host_activate(host, irq, ahci_level_irq_with_errata,
+ IRQF_SHARED, sht);
else
rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
IRQF_SHARED, sht);
--
2.1.0
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