From: Alan Stern <stern@rowland.harvard.edu>
Date: Mon, 27 Oct 2008 16:07:44 +0000 (-0400)
Subject: USB: prevent autosuspend during hub initialization
X-Git-Tag: v3.12-rc1~17429^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=61fbeba11c553c489ba5284c0ed67067dc7b7c0f;p=kernel%2Fkernel-generic.git

USB: prevent autosuspend during hub initialization

This patch (as1153) fixes a potential problem in hub initialization.
Starting in 2.6.28, initialization was split into several tasks to
help speed up booting.  This opens the possibility that the hub may be
autosuspended before all the initialization tasks can complete.

Normally that wouldn't matter, but with incomplete initialization
there is a risk that the hub would never autoresume -- especially if
devices were plugged into the hub beforehand.  The solution is a
simple one-line change to suppress autosuspend until the
initialization is finished.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 37ff8ae..b19cbfc 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -659,6 +659,9 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
 			schedule_delayed_work(&hub->init_work,
 					msecs_to_jiffies(delay));
+
+			/* Suppress autosuspend until init is done */
+			to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;
 			return;		/* Continues at init2: below */
 		} else {
 			hub_power_on(hub, true);