diff --git a/kernel/dev/ide.c b/kernel/dev/ide.c
index 0a2c602..51a6424 100644
--- a/kernel/dev/ide.c
+++ b/kernel/dev/ide.c
@@ -130,6 +130,18 @@ void
 ideinit(void)
 {
   initlock(&idelock, "ide");
+
+  // No controller at all: the bus floats and the status port reads 0xFF.
+  // That has BSY set, so idewait() below took it for a drive that was still
+  // busy and waited out its full second -- a second of every boot on q35 and
+  // on any PC whose disks are SATA, which is all of them. 0xFF is not a
+  // status any drive reports (BSY and DRDY are never both set), so it can be
+  // answered at once.
+  if(inb(0x1f7) == 0xFF){
+    kinfo("ide: no controller at the legacy ports\n");
+    return;
+  }
+
   // ISA signalling: edge-triggered, active high. Everything at a fixed
   // legacy port is wired this way; PCI devices are not.
   irq_register(IRQ_IDE, ide_irq, 0, "ide", 0);
diff --git a/kernel/drivers/storage/ahci/ahci.c b/kernel/drivers/storage/ahci/ahci.c
index 0b5b743..24733e9 100644
--- a/kernel/drivers/storage/ahci/ahci.c
+++ b/kernel/drivers/storage/ahci/ahci.c
@@ -167,9 +167,22 @@ port_stop(volatile uint8 *r)
 static int
 port_link(volatile uint8 *r)
 {
+  // A drive told to spin up a moment ago takes a few milliseconds to be seen
+  // at all; give it twenty before calling the port empty.
   uint32 ssts = rd(r, PX_SSTS);
+  for (int i = 0; i < 20 && (ssts & 0xF) == 0; i++) {
+    microdelay(1000);
+    ssts = rd(r, PX_SSTS);
+  }
   if ((ssts & 0xF) == 3)
     return 1;
+  // DET = 0 is "no device detected": an empty port, not a slow one. This
+  // used to COMRESET every empty port and wait a second for an answer that
+  // could not come -- four seconds of boot on a q35 with one disk, all of it
+  // with interrupts off. Only a device that is detected without a link
+  // (DET = 1) is worth the reset.
+  if ((ssts & 0xF) != 1)
+    return 0;
 
   wr(r, PX_SCTL, (rd(r, PX_SCTL) & ~0xFu) | 1);    // DET = 1: COMRESET
   microdelay(2000);                                  // at least 1 ms