---

yaml
---
r: 98281
b: refs/heads/master
c: c6112bd
h: refs/heads/master
i:
  98279: a735d41
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3bd0a70ee9cc30ae81b39cb5ecad0fa7bcb4675b
+refs/heads/master: c6112bd86bc8f727bb732a47f2133e0ff12beda9

trunk/drivers/ata/sata_mv.c

@@ -1595,6 +1595,24 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
 
 	if ((qc->tf.protocol != ATA_PROT_DMA) &&
 	    (qc->tf.protocol != ATA_PROT_NCQ)) {
+		static int limit_warnings = 10;
+		/*
+		 * Errata SATA#16, SATA#24: warn if multiple DRQs expected.
+		 *
+		 * Someday, we might implement special polling workarounds
+		 * for these, but it all seems rather unnecessary since we
+		 * normally use only DMA for commands which transfer more
+		 * than a single block of data.
+		 *
+		 * Much of the time, this could just work regardless.
+		 * So for now, just log the incident, and allow the attempt.
+		 */
+		if (limit_warnings && (qc->nbytes / qc->sect_size) > 1) {
+			--limit_warnings;
+			ata_link_printk(qc->dev->link, KERN_WARNING, DRV_NAME
+					": attempting PIO w/multiple DRQ: "
+					"this may fail due to h/w errata\n");
+		}
 		/*
 		 * We're about to send a non-EDMA capable command to the
 		 * port.  Turn off EDMA so there won't be problems accessing