Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6

[sfrench/cifs-2.6.git] / drivers / ata / sata_sil24.c

diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 46fbbe7f121c2da1ca115a383800ee9f3525da5c..233e886933959c63f3a5d8d1ea04df0f0a2dfb6b 100644 (file)
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -30,7 +30,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME       "sata_sil24"
-#define DRV_VERSION    "0.9"
+#define DRV_VERSION    "1.0"
 
 /*
  * Port request block (PRB) 32 bytes
@@ -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);