Hi, [add Li Jun to CC] > Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> hat am 24. August 2016 um 15:45 > geschrieben: > > > 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. according to ci_hdrc_probe() from the chipidea core the IRQ seems to be requested via devm_request_irq() with the flag IRQF_SHARED. I have the suspicion the following commit triggers the kernel panic: 43a404577a93 ("usb: chipidea: host: set host to be null after hcd is freed") I will validate this. > > Alan Stern > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html