Messages in this thread | | | Date | Mon, 1 Sep 2008 20:34:53 +0400 | From | Anton Vorontsov <> | Subject | Re: [PATCH] usb: add Freescale QE/CPM USB peripheral controller driver |
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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 <X.Xie@freescale.com> > Signed-off-by: Li Yang <leoli@freescale.com> > ---
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
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