Re: sleeping while atomic in dwc3_gadget_start

From: Felipe Balbi
Date: Thu Jun 27 2013 - 02:58:55 EST


On Wed, Jun 26, 2013 at 02:52:56PM -0700, Stephen Boyd wrote:
> Hi,
>
> I'm getting the folllowing BUG message on bootup with 3.10-rc5
>
> BUG: sleeping function called from invalid context at mm/slub.c:926
> in_atomic(): 1, irqs_disabled(): 128, pid: 1, name: swapper/0
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-rc5-gee3e35b-09316-ge78f3b35 #643
> [<c0014220>] (unwind_backtrace+0x0/0x120) from [<c001212c>] (show_stack+0x10/0x14)
> [<c001212c>] (show_stack+0x10/0x14) from [<c0143750>] (kmem_cache_alloc_trace+0x3c/0x210)
> [<c0143750>] (kmem_cache_alloc_trace+0x3c/0x210) from [<c00e0c60>] (request_threaded_irq+0x88/0x11c)
> [<c00e0c60>] (request_threaded_irq+0x88/0x11c) from [<c03bf53c>] (dwc3_gadget_start+0x198/0x200)
> [<c03bf53c>] (dwc3_gadget_start+0x198/0x200) from [<c03f7a5c>] (udc_bind_to_driver+0x70/0xd8)
> [<c03f7a5c>] (udc_bind_to_driver+0x70/0xd8) from [<c03f7b50>] (usb_gadget_probe_driver+0x8c/0xb8)
>
> and I suspect this problem was introduced in commit 8698e2acf
> (usb: dwc3: gadget: introduce and use enable/disable irq
> methods). Is there a fix for this problem? Can we just move the
> irq request outside the spinlock?

nice :-)

how about this ?

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index b5e5b35..a8e6b8b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1508,6 +1508,15 @@ static int dwc3_gadget_start(struct usb_gadget *g,
int irq;
u32 reg;

+ irq = platform_get_irq(to_platform_device(dwc->dev), 0);
+ ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
+ IRQF_SHARED | IRQF_ONESHOT, "dwc3", dwc);
+ if (ret) {
+ dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
+ irq, ret);
+ goto err0;
+ }
+
spin_lock_irqsave(&dwc->lock, flags);

if (dwc->gadget_driver) {
@@ -1515,7 +1524,7 @@ static int dwc3_gadget_start(struct usb_gadget *g,
dwc->gadget.name,
dwc->gadget_driver->driver.name);
ret = -EBUSY;
- goto err0;
+ goto err1;
}

dwc->gadget_driver = driver;
@@ -1551,41 +1560,33 @@ static int dwc3_gadget_start(struct usb_gadget *g,
ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false);
if (ret) {
dev_err(dwc->dev, "failed to enable %s\n", dep->name);
- goto err0;
+ goto err1;
}

dep = dwc->eps[1];
ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false);
if (ret) {
dev_err(dwc->dev, "failed to enable %s\n", dep->name);
- goto err1;
+ goto err2;
}

/* begin to receive SETUP packets */
dwc->ep0state = EP0_SETUP_PHASE;
dwc3_ep0_out_start(dwc);

- irq = platform_get_irq(to_platform_device(dwc->dev), 0);
- ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
- IRQF_SHARED | IRQF_ONESHOT, "dwc3", dwc);
- if (ret) {
- dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
- irq, ret);
- goto err1;
- }
-
dwc3_gadget_enable_irq(dwc);

spin_unlock_irqrestore(&dwc->lock, flags);

return 0;

-err1:
+err2:
__dwc3_gadget_ep_disable(dwc->eps[0]);

-err0:
+err1:
spin_unlock_irqrestore(&dwc->lock, flags);

+err0:
return ret;
}


--
balbi

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