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>

1 files changed, 24 insertions, 15 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 45785ec702a1..1539734bbbad 100644
--- 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;
         }