Index: src/sys/dev/ata/ata-all.c
===================================================================
RCS file: /ncvs/src/sys/dev/ata/ata-all.c,v
retrieving revision 1.289
diff -u -b -p -r1.289 ata-all.c
--- src/sys/dev/ata/ata-all.c	11 Jun 2008 06:44:58 -0000	1.289
+++ src/sys/dev/ata/ata-all.c	25 Jul 2008 10:06:00 -0000
@@ -889,6 +889,28 @@ ata_mode2str(int mode)
     }
 }
 
+static int
+ata_str2mode(const char *str)
+{
+	if (!strncasecmp(str, "BIOSPIO", 7)) return ATA_PIO;
+	if (!strncasecmp(str, "PIO0", 4)) return ATA_PIO0;
+	if (!strncasecmp(str, "PIO1", 4)) return ATA_PIO1;
+	if (!strncasecmp(str, "PIO2", 4)) return ATA_PIO2;
+	if (!strncasecmp(str, "PIO3", 4)) return ATA_PIO3;
+	if (!strncasecmp(str, "PIO4", 4)) return ATA_PIO4;
+	if (!strncasecmp(str, "WDMA2", 5)) return ATA_WDMA2;
+	if (!strncasecmp(str, "UDMA2", 5)) return ATA_UDMA2;
+	if (!strncasecmp(str, "UDMA33", 6)) return ATA_UDMA2;
+	if (!strncasecmp(str, "UDMA4", 5)) return ATA_UDMA4;
+	if (!strncasecmp(str, "UDMA66", 6)) return ATA_UDMA4;
+	if (!strncasecmp(str, "UDMA5", 5)) return ATA_UDMA5;
+	if (!strncasecmp(str, "UDMA100", 7)) return ATA_UDMA5;
+	if (!strncasecmp(str, "UDMA6", 5)) return ATA_UDMA6;
+	if (!strncasecmp(str, "UDMA133", 7)) return ATA_UDMA6;
+	if (!strncasecmp(str, "BIOSDMA", 7)) return ATA_DMA;
+	return -1;
+}
+
 int
 ata_pmode(struct ata_params *ap)
 {
@@ -952,6 +974,19 @@ ata_limit_mode(device_t dev, int mode, i
 {
     struct ata_device *atadev = device_get_softc(dev);
 
+    if (ata_delayed_attach) {
+	driver_t *drv = device_get_driver(dev);
+	const char *str = NULL;
+	int m;
+
+	if (drv && resource_string_value(drv->name, atadev->unit,
+				"mode", &str) == 0) {
+	    m = ata_str2mode(str);
+	    if (m >= ATA_PIO)
+		mode = m;
+	}
+    }
+
     if (maxmode && mode > maxmode)
 	mode = maxmode;