On Thursday, June 13, 2013 09:59:44 PM Rafael J. Wysocki wrote:
> On Friday, June 14, 2013 12:32:25 AM Jiang Liu wrote:
> > Current ACPI glue logic expects that physical devices are destroyed
> > before destroying companion ACPI devices, otherwise it will break the
> > ACPI unbind logic and cause following warning messages:
> > [ 185.026073] usb usb5: Oops, 'acpi_handle' corrupt
> > [ 185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
> > [ 185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
> > [ 180.013656] port1: Oops, 'acpi_handle' corrupt
> > Please refer to https://bugzilla.kernel.org/attachment.cgi?id=104321
> > for full log message.
>
> So my question is, did we have this problem before commit 3b63aaa70e1?
>
> If we did, then when did it start? Or was it present forever?
>
> > Above warning messages are caused by following scenario:
> > 1) acpi_dock_notifier_call() queues a task (T1) onto kacpi_hotplug_wq
> > 2) kacpi_hotplug_wq handles T1, which invokes acpi_dock_deferred_cb()
> > ->dock_notify()-> handle_eject_request()->hotplug_dock_devices()
> > 3) hotplug_dock_devices() first invokes registered hotplug callbacks to
> > destroy physical devices, then destroys all affected ACPI devices.
> > Everything seems perfect until now. But the acpiphp dock notification
> > handler will queue another task (T2) onto kacpi_hotplug_wq to really
> > destroy affected physical devices.
>
> Would not the solution be to modify it so that it didn't spawn the other
> task (T2), but removed the affected physical devices synchronously?
>
> > 4) kacpi_hotplug_wq finishes T1, and all affected ACPI devices have
> > been destroyed.
> > 5) kacpi_hotplug_wq handles T2, which destroys all affected physical
> > devices.
> >
> > So it breaks ACPI glue logic's expection because ACPI devices are destroyed
> > in step 3 and physical devices are destroyed in step 5.
> >
> > Signed-off-by: Jiang Liu <[email protected]>
> > Reported-by: Alexander E. Patrakov <[email protected]>
> > Cc: Bjorn Helgaas <[email protected]>
> > Cc: Yinghai Lu <[email protected]>
> > Cc: "Rafael J. Wysocki" <[email protected]>
> > Cc: [email protected]
> > Cc: [email protected]
> > Cc: [email protected]
> > ---
> > Hi Bjorn and Rafael,
> > The recursive lock changes haven't been tested yet, need help
> > from Alexander for testing.
>
> Well, let's just say I'm not a fan of recursive locks. Is that unavoidable
> here?
What about the appended patch (on top of [1/9], untested)?
Rafael
---
drivers/pci/hotplug/acpiphp_glue.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c
@@ -145,9 +145,20 @@ static int post_dock_fixups(struct notif
return NOTIFY_OK;
}
+static void handle_dock_event_func(acpi_handle handle, u32 event, void
*context)
+{
+ if (event == ACPI_NOTIFY_EJECT_REQUEST) {
+ struct acpiphp_func *func = context;
+
+ if (!acpiphp_disable_slot(func->slot))
+ acpiphp_eject_slot(func->slot);
+ } else {
+ handle_hotplug_event_func(handle, event, context);
+ }
+}
static const struct acpi_dock_ops acpiphp_dock_ops = {
- .handler = handle_hotplug_event_func,
+ .handler = handle_dock_event_func,
};
/* Check whether the PCI device is managed by native PCIe hotplug driver */
--
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