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path: root/drivers/ata/sata_sil24.c
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Diffstat (limited to 'drivers/ata/sata_sil24.c')
-rw-r--r--drivers/ata/sata_sil24.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index ef83e6b1e31..233e8869339 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -888,6 +888,16 @@ static inline void sil24_host_intr(struct ata_port *ap)
u32 slot_stat, qc_active;
int rc;
+ /* If PCIX_IRQ_WOC, there's an inherent race window between
+ * clearing IRQ pending status and reading PORT_SLOT_STAT
+ * which may cause spurious interrupts afterwards. This is
+ * unavoidable and much better than losing interrupts which
+ * happens if IRQ pending is cleared after reading
+ * PORT_SLOT_STAT.
+ */
+ if (ap->flags & SIL24_FLAG_PCIX_IRQ_WOC)
+ writel(PORT_IRQ_COMPLETE, port + PORT_IRQ_STAT);
+
slot_stat = readl(port + PORT_SLOT_STAT);
if (unlikely(slot_stat & HOST_SSTAT_ATTN)) {
@@ -895,9 +905,6 @@ static inline void sil24_host_intr(struct ata_port *ap)
return;
}
- if (ap->flags & SIL24_FLAG_PCIX_IRQ_WOC)
- writel(PORT_IRQ_COMPLETE, port + PORT_IRQ_STAT);
-
qc_active = slot_stat & ~HOST_SSTAT_ATTN;
rc = ata_qc_complete_multiple(ap, qc_active, sil24_finish_qc);
if (rc > 0)
@@ -910,7 +917,8 @@ static inline void sil24_host_intr(struct ata_port *ap)
return;
}
- if (ata_ratelimit())
+ /* spurious interrupts are expected if PCIX_IRQ_WOC */
+ if (!(ap->flags & SIL24_FLAG_PCIX_IRQ_WOC) && ata_ratelimit())
ata_port_printk(ap, KERN_INFO, "spurious interrupt "
"(slot_stat 0x%x active_tag %d sactive 0x%x)\n",
slot_stat, ap->active_tag, ap->sactive);