On Wed, 24 Aug 2016, Peter Chen wrote: > On Tue, Aug 23, 2016 at 09:17:02PM +0200, Stefan Wahren wrote: > > Hi, > > > > i'm using a iMX233-OLinuXino board and the kernel panics during shutdown > > with > > 4.8.0-rc2-next-20160819: > > > > [ 420.040000] ci_hdrc ci_hdrc.0: remove, state 1 > > [ 420.050000] usb usb1: USB disconnect, device number 1 > > [ 420.060000] usb 1-1: USB disconnect, device number 2 > > [ 420.060000] usb 1-1.1: USB disconnect, device number 3 > > [ 420.090000] smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' > > usb-ci_hdrc.0-1.1, > > smsc95xx USB 2.0 Ethernet > > [ 420.290000] ci_hdrc ci_hdrc.0: USB bus 1 deregistered > > [ 420.300000] Unable to handle kernel NULL pointer dereference at virtual > > address 00000118 > > [ 420.300000] pgd = c2ea4000 > > [ 420.300000] [00000118] *pgd=00000000 > > [ 420.300000] Internal error: Oops: 5 [#1] ARM > > [ 420.300000] Modules linked in: > > [ 420.300000] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted > > 4.8.0-rc2-next-20160819 #1 > > [ 420.300000] Hardware name: Freescale MXS (Device Tree) > > [ 420.300000] task: c3490000 task.stack: c348e000 > > [ 420.300000] PC is at usb_hcd_irq+0x0/0x34 > > [ 420.300000] LR is at ci_irq+0x58/0x12c
> I am afraid the hcd is freed before the interrupt triggered. Would you > please try below changes: > > diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c > index 96ae695..61237a9 100644 > --- a/drivers/usb/chipidea/host.c > +++ b/drivers/usb/chipidea/host.c > @@ -103,7 +103,7 @@ static const struct ehci_driver_overrides > ehci_ci_overrides = { > static irqreturn_t host_irq(struct ci_hdrc *ci) > { > - return usb_hcd_irq(ci->irq, ci->hcd); > + return ci->hcd ? usb_hcd_irq(ci->irq, ci->hcd) : IRQ_NONE; > } This should not be needed. Instead, the driver should make sure that the interrupt handler has been fully unregistered before the hcd is deallocated. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html