diff --git a/sys/dev/ahci/ahci.h b/sys/dev/ahci/ahci.h
--- a/sys/dev/ahci/ahci.h
+++ b/sys/dev/ahci/ahci.h
@@ -621,6 +621,7 @@
 #define AHCI_Q_NOCCS		0x00400000
 #define AHCI_Q_NOAUX		0x00800000
 #define AHCI_Q_IOMMU_BUSWIDE	0x01000000
+#define AHCI_Q_SLOWDEV		0x02000000
 
 #define AHCI_Q_BIT_STRING	\
 	"\020"			\
@@ -648,7 +649,8 @@
 	"\026MRVL_SR_DEL"	\
 	"\027NOCCS"		\
 	"\030NOAUX"		\
-	"\031IOMMU_BUSWIDE"
+	"\031IOMMU_BUSWIDE"	\
+	"\032SLOWDEV"
 
 int ahci_attach(device_t dev);
 int ahci_detach(device_t dev);
diff --git a/sys/dev/ahci/ahci.c b/sys/dev/ahci/ahci.c
--- a/sys/dev/ahci/ahci.c
+++ b/sys/dev/ahci/ahci.c
@@ -2605,10 +2605,14 @@
 ahci_sata_connect(struct ahci_channel *ch)
 {
 	u_int32_t status;
-	int timeout, found = 0;
+	int timeout, timeoutslot, found = 0;
 
-	/* Wait up to 100ms for "connect well" */
-	for (timeout = 0; timeout < 1000 ; timeout++) {
+	/*
+	 * Wait for "connect well", up to 100ms by default and
+	 * up to 500ms for devices with the SLOWDEV quirk.
+	 */
+	timeoutslot = ((ch->quirks & AHCI_Q_SLOWDEV) ? 5000 : 1000);
+	for (timeout = 0; timeout < timeoutslot; timeout++) {
 		status = ATA_INL(ch->r_mem, AHCI_P_SSTS);
 		if ((status & ATA_SS_DET_MASK) != ATA_SS_DET_NO_DEVICE)
 			found = 1;
@@ -2627,7 +2631,7 @@
 			break;
 		DELAY(100);
 	}
-	if (timeout >= 1000 || !found) {
+	if (timeout >= timeoutslot || !found) {
 		if (bootverbose) {
 			device_printf(ch->dev,
 			    "SATA connect timeout time=%dus status=%08x\n",
diff --git a/sys/dev/ahci/ahci_pci.c b/sys/dev/ahci/ahci_pci.c
--- a/sys/dev/ahci/ahci_pci.c
+++ b/sys/dev/ahci/ahci_pci.c
@@ -293,7 +293,7 @@
 	{0x92201b4b, 0x00, "Marvell 88SE9220",  AHCI_Q_ALTSIG |
 	    AHCI_Q_IOMMU_BUSWIDE},
 	{0x92301b4b, 0x00, "Marvell 88SE9230",  AHCI_Q_ALTSIG |
-	    AHCI_Q_IOMMU_BUSWIDE},
+	    AHCI_Q_IOMMU_BUSWIDE | AHCI_Q_SLOWDEV},
 	{0x92351b4b, 0x00, "Marvell 88SE9235",  0},
 	{0x06201103, 0x00, "HighPoint RocketRAID 620",	0},
 	{0x06201b4b, 0x00, "HighPoint RocketRAID 620",	0},