--- linux-2.6.20-rc5/drivers/ata/sata_nv.c	2007-01-19 19:18:53.000000000 -0600
+++ linux-2.6.20-rc5debug/drivers/ata/sata_nv.c	2007-01-21 13:35:17.000000000 -0600
@@ -509,14 +509,38 @@ static void nv_adma_register_mode(struct
 {
 	void __iomem *mmio = nv_adma_ctl_block(ap);
 	struct nv_adma_port_priv *pp = ap->private_data;
-	u16 tmp;
+	u16 tmp, status;
+	int count = 0;
 
 	if (pp->flags & NV_ADMA_PORT_REGISTER_MODE)
 		return;
 
+	status = readw(mmio + NV_ADMA_STAT);
+	while(!(status & NV_ADMA_STAT_IDLE) && count < 20) {
+		ndelay(50);
+		status = readw(mmio + NV_ADMA_STAT);
+		count++;
+	}
+	if(count == 20)
+		ata_port_printk(ap, KERN_WARNING,
+			"timeout waiting for ADMA IDLE, stat=0x%hx\n",
+			status);
+
 	tmp = readw(mmio + NV_ADMA_CTL);
 	writew(tmp & ~NV_ADMA_CTL_GO, mmio + NV_ADMA_CTL);
 
+	count = 0;
+	status = readw(mmio + NV_ADMA_STAT);
+	while(!(status & NV_ADMA_STAT_LEGACY) && count < 20) {
+		ndelay(50);
+		status = readw(mmio + NV_ADMA_STAT);
+		count++;
+	}
+	if(count == 20)
+		ata_port_printk(ap, KERN_WARNING,
+			 "timeout waiting for ADMA LEGACY, stat=0x%hx\n",
+			 status);
+
 	pp->flags |= NV_ADMA_PORT_REGISTER_MODE;
 }
 
@@ -524,7 +548,8 @@ static void nv_adma_mode(struct ata_port
 {
 	void __iomem *mmio = nv_adma_ctl_block(ap);
 	struct nv_adma_port_priv *pp = ap->private_data;
-	u16 tmp;
+	u16 tmp, status;
+	int count = 0;
 
 	if (!(pp->flags & NV_ADMA_PORT_REGISTER_MODE))
 		return;
@@ -534,6 +559,18 @@ static void nv_adma_mode(struct ata_port
 	tmp = readw(mmio + NV_ADMA_CTL);
 	writew(tmp | NV_ADMA_CTL_GO, mmio + NV_ADMA_CTL);
 
+	status = readw(mmio + NV_ADMA_STAT);
+	while(((status & NV_ADMA_STAT_LEGACY) ||
+	      !(status & NV_ADMA_STAT_IDLE)) && count < 20) {
+		ndelay(50);
+		status = readw(mmio + NV_ADMA_STAT);
+		count++;
+	}
+	if(count == 20)
+		ata_port_printk(ap, KERN_WARNING,
+			"timeout waiting for ADMA LEGACY clear and IDLE, stat=0x%hx\n",
+			status);
+
 	pp->flags &= ~NV_ADMA_PORT_REGISTER_MODE;
 }