ahci: improve spurious SDB FIS handling

Spurious SDB FIS during NCQ might not contain spurious completions.
It could be spurious TF update or invalid async notification.  Treat
as HSM violation iff a spurious SDB FIS contains spurious completions;
otherwise, just whine once about it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 45785ec..1539734 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -200,6 +200,7 @@ struct ahci_port_priv {
        /* for NCQ spurious interrupt analysis */
        unsigned int            ncq_saw_d2h:1;
        unsigned int            ncq_saw_dmas:1;
+       unsigned int            ncq_saw_sdb:1;
 };
 
 static u32 ahci_scr_read (struct ata_port *ap, unsigned int sc_reg);
@@ -1157,23 +1158,31 @@ static void ahci_host_intr(struct ata_port *ap)
        }
 
        if (status & PORT_IRQ_SDB_FIS) {
-               /* SDB FIS containing spurious completions might be
-                * dangerous, whine and fail commands with HSM
-                * violation.  EH will turn off NCQ after several such
-                * failures.
-                */
                const __le32 *f = pp->rx_fis + RX_FIS_SDB;
 
-               ata_ehi_push_desc(ehi, "spurious completion during NCQ "
-                                 "issue=0x%x SAct=0x%x FIS=%08x:%08x",
-                                 readl(port_mmio + PORT_CMD_ISSUE),
-                                 readl(port_mmio + PORT_SCR_ACT),
-                                 le32_to_cpu(f[0]), le32_to_cpu(f[1]));
-
-               ehi->err_mask |= AC_ERR_HSM;
-               ehi->action |= ATA_EH_SOFTRESET;
-               ata_port_freeze(ap);
-
+               if (le32_to_cpu(f[1])) {
+                       /* SDB FIS containing spurious completions
+                        * might be dangerous, whine and fail commands
+                        * with HSM violation.  EH will turn off NCQ
+                        * after several such failures.
+                        */
+                       ata_ehi_push_desc(ehi,
+                               "spurious completions during NCQ "
+                               "issue=0x%x SAct=0x%x FIS=%08x:%08x",
+                               readl(port_mmio + PORT_CMD_ISSUE),
+                               readl(port_mmio + PORT_SCR_ACT),
+                               le32_to_cpu(f[0]), le32_to_cpu(f[1]));
+                       ehi->err_mask |= AC_ERR_HSM;
+                       ehi->action |= ATA_EH_SOFTRESET;
+                       ata_port_freeze(ap);
+               } else {
+                       if (!pp->ncq_saw_sdb)
+                               ata_port_printk(ap, KERN_INFO,
+                                       "spurious SDB FIS %08x:%08x during NCQ, "
+                                       "this message won't be printed again\n",
+                                       le32_to_cpu(f[0]), le32_to_cpu(f[1]));
+                       pp->ncq_saw_sdb = 1;
+               }
                known_irq = 1;
        }