diff --git a/sys/dev/ahci/ahci.c b/sys/dev/ahci/ahci.c
index 32a359c930e..e05dd7033b6 100644
--- a/sys/dev/ahci/ahci.c
+++ b/sys/dev/ahci/ahci.c
@@ -668,8 +668,8 @@ ahci_ch_attach(device_t dev)
 		return (ENXIO);
 	ahci_dmainit(dev);
 	ahci_slotsalloc(dev);
-	ahci_ch_init(dev);
 	mtx_lock(&ch->mtx);
+	ahci_ch_init(dev);
 	rid = ATA_IRQ_RID;
 	if (!(ch->r_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
 	    &rid, RF_SHAREABLE | RF_ACTIVE))) {