6563214 System panics on booting Solaris from USB hard/flash drive if it connected via usb hub

2 files changed, 21 insertions, 1 deletions

diff --git a/usr/src/uts/common/io/usb/usba/hubdi.c b/usr/src/uts/common/io/usb/usba/hubdi.c
index 8cfb0ea45e..9fe61a8244 100644
--- a/usr/src/uts/common/io/usb/usba/hubdi.c
+++ b/usr/src/uts/common/io/usb/usba/hubdi.c
@@ -1295,8 +1295,15 @@ hubd_bus_config(dev_info_t *dip, uint_t flag, ddi_bus_config_op_t op,
 	/*
 	 * there must be a smarter way to do this but for
 	 * now, a hack for booting USB storage.
+	 *
+	 * NOTE: we want to delay the mountroot thread which
+	 * exclusively does a BUS_CONFIG_ONE, but not the
+	 * USB hotplug threads which do the asynchronous
+	 * enumeration exlusively via BUS_CONFIG_ALL. Having
+	 * a delay for USB hotplug threads negates the delay for
+	 * mountroot resulting in mountroot failing.
 	 */
-	if (!modrootloaded) {
+	if (!modrootloaded && op == BUS_CONFIG_ONE) {
 		delay(drv_usectohz(1000000));
 	}
 	ndi_devi_enter(hubd->h_dip, &circ);
diff --git a/usr/src/uts/common/os/swapgeneric.c b/usr/src/uts/common/os/swapgeneric.c
index d4217c77f3..011a6a3c4d 100644
--- a/usr/src/uts/common/os/swapgeneric.c
+++ b/usr/src/uts/common/os/swapgeneric.c
@@ -906,6 +906,19 @@ load_bootpath_drivers(char *bootpath)
 		return (NULL);
 	}
 
+	/*
+	 * The PROM node for hubs have incomplete compatible
+	 * properties and therefore do not bind to the hubd driver.
+	 * As a result load_bootpath_drivers() loads the usb_mid driver
+	 * for hub nodes rather than the hubd driver. This causes
+	 * mountroot failures when booting off USB storage. To prevent
+	 * this, if we are booting via USB hubs, we preload the hubd driver.
+	 */
+	if (strstr(bootpath, "/hub@") && modloadonly("drv", "hubd") == -1) {
+		cmn_err(CE_WARN, "bootpath contains a USB hub, "
+		    "but cannot load hubd driver");
+	}
+
 	/* get rid of minor node at end of copy (if not already done above) */
 	p = strrchr(pathcopy, '/');
 	if (p) {