MFC r310242:

Defer USB enumeration until the SI_SUB_KICK_SCHEDULER is executed to avoid
boot panics in conjunction with the recently added EARLY_AP_STARTUP feature.
The panics happen due to using kernel facilities like callouts too early.

Tested by:	jhb @

2 files changed, 27 insertions, 1 deletions

diff --git a/sys/dev/usb/usb_hub.c b/sys/dev/usb/usb_hub.c
index 354e62d..7d74dd8 100644
--- a/sys/dev/usb/usb_hub.c
+++ b/sys/dev/usb/usb_hub.c
@@ -2272,6 +2272,11 @@ usb_needs_explore(struct usb_bus *bus, uint8_t do_probe)
 
 	DPRINTF("\n");
 
+	if (cold != 0) {
+		DPRINTF("Cold\n");
+		return;
+	}
+
 	if (bus == NULL) {
 		DPRINTF("No bus pointer!\n");
 		return;
@@ -2337,6 +2342,26 @@ usb_needs_explore_all(void)
 }
 
 /*------------------------------------------------------------------------*
+ *	usb_needs_explore_init
+ *
+ * This function will ensure that the USB controllers are not enumerated
+ * until the "cold" variable is cleared.
+ *------------------------------------------------------------------------*/
+static void
+usb_needs_explore_init(void *arg)
+{
+	/*
+	 * The cold variable should be cleared prior to this function
+	 * being called:
+	 */
+	if (cold == 0)
+		usb_needs_explore_all();
+	else
+		DPRINTFN(-1, "Cold variable is still set!\n");
+}
+SYSINIT(usb_needs_explore_init, SI_SUB_KICK_SCHEDULER, SI_ORDER_SECOND, usb_needs_explore_init, NULL);
+
+/*------------------------------------------------------------------------*
  *	usb_bus_power_update
  *
  * This function will ensure that all USB devices on the given bus are
diff --git a/sys/dev/usb/usb_process.c b/sys/dev/usb/usb_process.c
index e70166c..0f17485 100644
--- a/sys/dev/usb/usb_process.c
+++ b/sys/dev/usb/usb_process.c
@@ -455,14 +455,15 @@ usb_proc_drain(struct usb_process *up)
 			up->up_csleep = 0;
 			cv_signal(&up->up_cv);
 		}
+#ifndef EARLY_AP_STARTUP
 		/* Check if we are still cold booted */
-
 		if (cold) {
 			USB_THREAD_SUSPEND(up->up_ptr);
 			printf("WARNING: A USB process has "
 			    "been left suspended\n");
 			break;
 		}
+#endif
 		cv_wait(&up->up_cv, up->up_mtx);
 	}
 	/* Check if someone is waiting - should not happen */