From: Kevin Hilman <khilman@mvista.com>
Date: Wed, 20 Feb 2008 17:27:10 +0000 (-0800)
Subject: ARM: OMAP: MUSB: prevent recursive spinlock in TX path
X-Git-Tag: v2.6.25-omap1~153
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?p=linux-2.6-omap-h63xx.git;a=commitdiff_plain;h=4bbf5ebf1fdedd08d84c80a8ba011fd353d8fc5b

ARM: OMAP: MUSB: prevent recursive spinlock in TX path

If a hard IRQ occurs during the soft IRQ TX processing, a recursive
spinlock BUG can occur.

Prevent this by interrupt-off locking around usb_hcd_link_urb_to_ep()

Found while testing bluetooth A2DP audio over USB.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 2ad2ed95404..82e12655dc8 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1757,7 +1757,9 @@ static int musb_urb_enqueue(
 	if (!is_host_active(musb) || !musb->is_active)
 		return -ENODEV;
 
+	spin_lock_irqsave(&musb->lock, flags);
 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
+	spin_unlock_irqrestore(&musb->lock, flags);
 	if (ret)
 		return ret;