Re: [linux-pm] [PATCH 8/9] PCI / ACPI / PM: Platform support for PCI PME wake-up (rev. 7)

From: Rafael J. Wysocki
Date: Tue Feb 09 2010 - 15:19:21 EST


On Tuesday 09 February 2010, Gary Hade wrote:
> On Tue, Feb 09, 2010 at 08:41:16AM -0800, Gary Hade wrote:
> > On Tue, Feb 09, 2010 at 01:48:20PM +0100, Rafael J. Wysocki wrote:
> > > On Tuesday 09 February 2010, Gary Hade wrote:
> > > > On Mon, Feb 08, 2010 at 03:37:08PM -0800, Gary Hade wrote:
> > > > > On Mon, Feb 08, 2010 at 10:30:30PM +0100, Rafael J. Wysocki wrote:
> > > > > > On Monday 08 February 2010, Rafael J. Wysocki wrote:
> > > > > > > On Monday 08 February 2010, Gary Hade wrote:
> > > > > > > > On Sat, Feb 06, 2010 at 09:11:56PM +0100, Rafael J. Wysocki wrote:
> > > > > > > > > On Saturday 06 February 2010, Bjorn Helgaas wrote:
> > > > > > > > > > On Sunday 10 January 2010 07:01:03 am Rafael J. Wysocki wrote:
> > > > > > > > > > > From: Rafael J. Wysocki <rjw@xxxxxxx>
> > > > > > > > > > >
> > > > > > > > > > > Although the majority of PCI devices can generate PMEs that in
> > > > > > > > > > > principle may be used to wake up devices suspended at run time,
> > > > > > > > > > > platform support is generally necessary to convert PMEs into wake-up
> > > > > > > > > > > events that can be delivered to the kernel. If ACPI is used for this
> > > > > > > > > > > purpose, a PME generated by a PCI device will trigger the ACPI GPE
> > > > > > > > > > > associated with the device to generate an ACPI wake-up event that we
> > > > > > > > > > > can set up a handler for, provided that everything is configured
> > > > > > > > > > > correctly.
> > > > > > > > > >
> > > > > > > > > > I think acpiphp needs a little attention after this patch. Gary
> > > > > > > > > > Hade noticed while testing Jesse's linux-next branch that acpiphp
> > > > > > > > > > complains like this:
> > > > > > > > > >
> > > > > > > > > > acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
> > > > > > > > > > acpiphp: Slot [9] registered
> > > > > > > > > > acpiphp: Slot [10] registered
> > > > > > > > > > acpiphp_glue: failed to register interrupt notify handler
> > > > > > > > > > acpiphp: Slot [6] registered
> > > > > > > > > > acpiphp_glue: failed to register interrupt notify handler
> > > > > > > > > >
> > > > > > > > > > I reproduced this on an HP rx3600 (ia64), and found that acpiphp
> > > > > > > > > > doesn't complain on commit 82533a617f453, but it *does* complain
> > > > > > > > > > on commit fb3383bb4ac6e, which seems to be this patch.
> > > > > > > > >
> > > > > > > > > I can't see the possible reason looking at the code alone.
> > > > > > > > >
> > > > > > > > > Could you add a debug printk() printing the error code returned by
> > > > > > > > > pci_acpi_add_hp_notifier() in acpiphp_glue.c:register_slot(), please?
> > > > > > > >
> > > > > > > > Rafael, On the system where I ran into the problem it returns
> > > > > > > > AE_NOT_FOUND. See below.
> > > > > > >
> > > > > > > Thanks!
> > > > > > >
> > > > > > > Well, that means there's no struct acpi_device object associated with handle.
> > > > > > >
> > > > > > > I must admit I didn't take that into consideration, but it should be easily
> > > > > > > fixable. I'll send a patch for that later today.
> > > > > >
> > > > > > Patch appended.
> > > > > >
> > > > > > If the theory is correct, it should fix the issue. Please test.
> > > > >
> > > > > Well, acpiphp now loads OK with no disturbing messages:
> > > > > [ 247.360878] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
> > > > > [ 247.385048] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
> > > > > [ 247.385459] acpiphp_glue: found PCI host-bus bridge with hot-pluggable slots
> > > > > [ 247.385486] acpiphp_glue: found ACPI PCI Hotplug slot 1 at PCI 0000:02:01
> > > > > [ 247.385519] acpiphp: Slot [1] registered
> > > > > [ 247.386167] acpiphp_glue: found PCI host-bus bridge with hot-pluggable slots
> > > > > [ 247.386196] acpiphp_glue: found ACPI PCI Hotplug slot 2 at PCI 0000:06:01
> > > > > [ 247.386225] acpiphp: Slot [2] registered
> > > > > [ 247.386828] acpiphp_glue: found PCI-to-PCI bridge at PCI 0000:0a:00.0
> > > > > [ 247.386861] acpiphp_glue: found ACPI PCI Hotplug slot 3 at PCI 0000:0b:00
> > > > > [ 247.386902] acpiphp: Slot [3] registered
> > > > > [ 247.387564] acpiphp_glue: found PCI-to-PCI bridge at PCI 0000:0f:00.0
> > > > > [ 247.387597] acpiphp_glue: found ACPI PCI Hotplug slot 4 at PCI 0000:10:00
> > > > > [ 247.387620] acpiphp: Slot [4] registered
> > > > > [ 247.388293] acpiphp_glue: found PCI-to-PCI bridge at PCI 0000:14:00.0
> > > > > [ 247.388324] acpiphp_glue: found ACPI PCI Hotplug slot 5 at PCI 0000:15:00
> > > > > [ 247.388347] acpiphp: Slot [5] registered
> > > > > [ 247.389041] acpiphp_glue: found PCI-to-PCI bridge at PCI 0000:19:00.0
> > > > > [ 247.389077] acpiphp_glue: found ACPI PCI Hotplug slot 6 at PCI 0000:1a:00
> > > > > [ 247.389114] acpiphp: Slot [6] registered
> > > > > [ 247.389736] acpiphp_glue: Bus 0000:1a has 1 slot
> > > > > [ 247.389739] acpiphp_glue: Bus 0000:15 has 1 slot
> > > > > [ 247.389742] acpiphp_glue: Bus 0000:10 has 1 slot
> > > > > [ 247.389746] acpiphp_glue: Bus 0000:0b has 1 slot
> > > > > [ 247.389748] acpiphp_glue: Bus 0000:06 has 1 slot
> > > > > [ 247.389751] acpiphp_glue: Bus 0000:02 has 1 slot
> > > > > [ 247.389753] acpiphp_glue: Total 6 slots
> > > > >
> > > > > However, I didn't have a chance to confirm that hot-add of a
> > > > > PCI card works correctly before someone else swiped the system
> > > > > from me for a while. I will verify this when I get it back,
> > > > > hopefully later today.
> > > >
> > > > I got the system back but unfortunately have some bad news.
> > > > The system has 2 hotpluggable PCI-X slots and 4 hotpluggable
> > > > PCIe slots. I tried hot-adding both a PCI-X card and a PCIe
> > > > card but acpiphp did not seem to see the hot-add event for
> > > > either card. acpiphp was loaded with debug=1 and issued no
> > > > messages when I added the cards.
> > >
> > > I gather it works without the $subject patch?
> >
> > I don't know for sure. Late Friday after running into the handler
> > registration issue I reverted 8/9 which required hand fixup for
> > one hunk failure. I then got some compile errors which I assumed
> > may be related to my non-removal of some of the other patches in the
> > series. I started reverting the entire series but got a failure right
> > away with 9/9 but didn't take the time to try to resolve it.
> >
> > Since it sounds like you are doubtful that your changes are
> > responsible for this new issue I will try to make time to fuss
> > with this more today.
>
> Rafael, I think I can approach this from a different direction.
> Except for a trivial failure with 9/9, the entire series applies
> to 2.6.33-rc7. I will try hot-add with 2.6.33-rc7 with and without
> your patches and let you know what happens.

Yes, please, but you may want to test the appended patch first.

If I think correctly what the problem is, it should work.

Rafael

---
drivers/pci/hotplug/acpiphp_glue.c | 4 ++++
drivers/pci/pci-acpi.c | 30 ++++++++++++++++++++++++------
2 files changed, 28 insertions(+), 6 deletions(-)

Index: linux-2.6/drivers/pci/pci-acpi.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-acpi.c
+++ linux-2.6/drivers/pci/pci-acpi.c
@@ -116,10 +116,19 @@ acpi_status pci_acpi_add_hp_notifier(acp
{
struct pci_acpi_notify_data *nd;
struct acpi_device *dev;
- acpi_status status = AE_OK;
+ acpi_status status;
+
+ if (!handle)
+ return AE_BAD_PARAMETER;

- if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev)))
- return AE_NOT_FOUND;
+ status = acpi_bus_get_device(handle, &dev);
+ /*
+ * If there's no struct acpi_device for given handle, try to install the
+ * handler directly.
+ */
+ if (ACPI_FAILURE(status))
+ return acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ handler, context);

mutex_lock(&pci_acpi_notifier_mtx);

@@ -170,10 +179,19 @@ acpi_status pci_acpi_remove_hp_notifier(
{
struct pci_acpi_notify_data *nd;
struct acpi_device *dev;
- acpi_status status = AE_NOT_FOUND;
+ acpi_status status;
+
+ if (!handle)
+ return AE_BAD_PARAMETER;

- if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev)))
- return AE_NOT_FOUND;
+ status = acpi_bus_get_device(handle, &dev);
+ /*
+ * If there's no struct acpi_device for given handle, try to remove the
+ * handler directly.
+ */
+ if (ACPI_FAILURE(status))
+ return acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ handler);

mutex_lock(&pci_acpi_notifier_mtx);

Index: linux-2.6/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-2.6.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-2.6/drivers/pci/hotplug/acpiphp_glue.c
@@ -1140,8 +1140,12 @@ static void handle_hotplug_event_bridge(
int num_sub_bridges = 0;

if (acpi_bus_get_device(handle, &device)) {
+ pci_acpi_remove_hp_notifier(handle,
+ handle_hotplug_event_bridge);
/* This bridge must have just been physically inserted */
handle_bridge_insertion(handle, type);
+ pci_acpi_add_hp_notifier(handle, handle_hotplug_event_bridge,
+ context);
return;
}

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