On Wed, May 05, 2021 at 02:09:17PM +0200, Greg KH wrote:
> On Wed, May 05, 2021 at 02:01:17PM +0200, Pali Rohár wrote:
> > [ 72.511899] Internal error: synchronous external abort: 96000210 [#1] SMP
[...]
> > [ 72.636415] Call trace:
> > [ 72.638936] xhci_irq+0x70/0x17b8
> > [ 72.642360] usb_hcd_irq+0x34/0x50
> > [ 72.645876] usb_hcd_pci_remove+0x78/0x138
> > [ 72.650106] xhci_pci_remove+0x6c/0xa8
> > [ 72.653978] pci_device_remove+0x44/0x108
> > [ 72.658122] device_release_driver_internal+0x110/0x1e0
> > [ 72.663521] device_release_driver+0x1c/0x28
> > [ 72.667931] pci_stop_bus_device+0x84/0xc0
> > [ 72.672162] pci_stop_and_remove_bus_device+0x1c/0x30
> > [ 72.677373] pciehp_unconfigure_device+0x98/0xf8
> > [ 72.682138] pciehp_disable_slot+0x60/0x118
> > [ 72.686457] pciehp_handle_presence_or_link_change+0xec/0x3b0
> > [ 72.692386] pciehp_ist+0x170/0x1a0
> > [ 72.695984] irq_thread_fn+0x30/0x90
^^^^^^^^^^^^^
[...]
> > I suspect that issue is in usb_hcd_pci_remove() function which calls
> > local_irq_disable()+usb_hcd_irq()+local_irq_enable() functions but do
> > not take into care that whole usb_hcd_pci_remove() function may be
> > called from interrupt context.
>
> usb_hcd_pci_remove() should NOT be called from interrupt context.
>
> What is causing that to happen?
Nothing. It's called from an IRQ *thread*, i.e. task context, see above.
> > Can you look at this issue if it is really safe to call usb_hcd_irq()
> > from interrupt context? Or rather if it is safe to call functions like
> > pciehp_disable_slot() or device_release_driver() from interrupt context
> > like it can be seen in call trace?
>
> What is removing devices from an irq? That is wrong, pci hotplug never
> used to do that, what recently changed?
Nothing changed, the allegation that something is called from interrupt
context is wrong.
Thanks,
Lukas
