sata_mv: don't issue two DMA commands concurrently

[linux-2.6-omap-h63xx.git] / drivers / ata / sata_mv.c

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index ad169ffbc4cb2a0ad8387c478b6a9540992f99b6..80c655f85bc85f4d18d5b0bd6aa3d1c10a266fb0 100644 (file)
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1134,30 +1134,16 @@ static int mv_qc_defer(struct ata_queued_cmd *qc)
        if (ap->nr_active_links == 0)
                return 0;
 
-       if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) {
-               /*
-                * The port is operating in host queuing mode (EDMA).
-                * It can accomodate a new qc if the qc protocol
-                * is compatible with the current host queue mode.
-                */
-               if (pp->pp_flags & MV_PP_FLAG_NCQ_EN) {
-                       /*
-                        * The host queue (EDMA) is in NCQ mode.
-                        * If the new qc is also an NCQ command,
-                        * then allow the new qc.
-                        */
-                       if (qc->tf.protocol == ATA_PROT_NCQ)
-                               return 0;
-               } else {
-                       /*
-                        * The host queue (EDMA) is in non-NCQ, DMA mode.
-                        * If the new qc is also a non-NCQ, DMA command,
-                        * then allow the new qc.
-                        */
-                       if (qc->tf.protocol == ATA_PROT_DMA)
-                               return 0;
-               }
-       }
+       /*
+        * The port is operating in host queuing mode (EDMA) with NCQ
+        * enabled, allow multiple NCQ commands.  EDMA also allows
+        * queueing multiple DMA commands but libata core currently
+        * doesn't allow it.
+        */
+       if ((pp->pp_flags & MV_PP_FLAG_EDMA_EN) &&
+           (pp->pp_flags & MV_PP_FLAG_NCQ_EN) && ata_is_ncq(qc->tf.protocol))
+               return 0;
+
        return ATA_DEFER_PORT;
 }