[libata ahci] error handling fixes

Needed to get ATAPI working.

- dump hardware error bits, if hardware signals an error
- only reset hardware during timeout if a command was active
- call ata_qc_complete() with a fine-grained error mask.
  Needed so that atapi_qc_complete() can distinguish between
  device errors and other errors.

diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 4e96ec5f2ff94f003a5fe06ee75d92ae5603ec54..c710a7def7a7fd2024ea18be6ac7cfe31a382624 100644 (file)
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -603,7 +603,12 @@ static void ahci_intr_error(struct ata_port *ap, u32 irq_stat)
        writel(tmp, port_mmio + PORT_CMD);
        readl(port_mmio + PORT_CMD); /* flush */
 
-       printk(KERN_WARNING "ata%u: error occurred, port reset\n", ap->id);
+       printk(KERN_WARNING "ata%u: error occurred, port reset (%s%s%s%s)\n",
+              ap->id,
+              irq_stat & PORT_IRQ_TF_ERR ? "taskf " : "",
+              irq_stat & PORT_IRQ_HBUS_ERR ? "hbus " : "",
+              irq_stat & PORT_IRQ_HBUS_DATA_ERR ? "hbus_data " : "",
+              irq_stat & PORT_IRQ_IF_ERR ? "if " : "");
 }
 
 static void ahci_eng_timeout(struct ata_port *ap)
@@ -618,13 +623,13 @@ static void ahci_eng_timeout(struct ata_port *ap)
 
        spin_lock_irqsave(&host_set->lock, flags);
 
-       ahci_intr_error(ap, readl(port_mmio + PORT_IRQ_STAT));
-
        qc = ata_qc_from_tag(ap, ap->active_tag);
        if (!qc) {
                printk(KERN_ERR "ata%u: BUG: timeout without command\n",
                       ap->id);
        } else {
+               ahci_intr_error(ap, readl(port_mmio + PORT_IRQ_STAT));
+
                /* hack alert!  We cannot use the supplied completion
                 * function from inside the ->eh_strategy_handler() thread.
                 * libata is the only user of ->eh_strategy_handler() in
@@ -659,9 +664,18 @@ static inline int ahci_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
        }
 
        if (status & PORT_IRQ_FATAL) {
-               ahci_intr_error(ap, status);
+               unsigned int err_mask;
+               if (status & PORT_IRQ_TF_ERR)
+                       err_mask = AC_ERR_DEV;
+               else if (status & PORT_IRQ_IF_ERR)
+                       err_mask = AC_ERR_ATA_BUS;
+               else
+                       err_mask = AC_ERR_HOST_BUS;
+
+               if (err_mask != AC_ERR_DEV)
+                       ahci_intr_error(ap, status);
                if (qc)
-                       ata_qc_complete(qc, AC_ERR_OTHER);
+                       ata_qc_complete(qc, err_mask);
        }
 
        return 1;