From: Lukas Wunner <lukas@wunner.de>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "Pali Rohár" <pali@kernel.org>,
linux-usb@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, "Marek Behún" <kabel@kernel.org>
Subject: Re: xhci_pci & PCIe hotplug crash
Date: Wed, 5 May 2021 14:37:53 +0200 [thread overview]
Message-ID: <20210505123753.GA29101@wunner.de> (raw)
In-Reply-To: <YJKK7SDIaeH1L/fC@kroah.com>
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
prev parent reply other threads:[~2021-05-05 12:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 12:01 xhci_pci & PCIe hotplug crash Pali Rohár
2021-05-05 12:09 ` Greg KH
2021-05-05 12:33 ` Pali Rohár
2021-05-05 12:40 ` Greg KH
2021-05-05 12:44 ` Lukas Wunner
2021-05-05 13:02 ` Pali Rohár
2021-05-05 15:20 ` David Laight
2021-05-05 15:39 ` Pali Rohár
2021-06-19 7:53 ` Lukas Wunner
2021-06-19 8:55 ` Pali Rohár
2021-05-05 12:37 ` Lukas Wunner [this message]
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