On Thu, Aug 28, 2008 at 05:43:33PM +0800, Li Yang wrote:

Some of Freescale SoC chips have a QE or CPM co-processor which
supports full speed USB.  The driver adds device mode support
of both QE and CPM USB controller to Linux USB gadget.  The
driver is tested with MPC8360 and MPC8272, and should work with
other models having QE/CPM given minor tweaks.

Signed-off-by: Xie Xiaobo <redacted>
Signed-off-by: Li Yang <redacted>
---

Just found a recursive locking bug:

[...]

+static int reset_queues(struct qe_udc *udc)
+{

Note: this function is called from the IRQ, the IRQ handler
grabs udc->lock spinlock..

+	u8 pipe;
+
+	for (pipe = 0; pipe < USB_MAX_ENDPOINTS; pipe++)
+		udc_reset_ep_queue(udc, pipe);
+
+	/* report disconnect; the driver is already quiesced */
+	udc->driver->disconnect(&udc->gadget);

In the disconnect(), g_ether driver will immediately call
qe_ep_disable() function which will try to grab &udc->lock
spinlock once again..

Not sure how to fix this properly... :-/

p.s. the same bug exists in omap_udc.c, pxa27x_udc.c and probably
other drivers as well... The only reason why it does not exploit
in most cases is that the spin_lock_irqsave for !SMP case turns
into simple local_irq_save().

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2