From: Tirumalesh Chalamarla <[email protected]> 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 <[email protected]> --- 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
