On Thu, Apr 25, 2013 at 06:47:07PM -0700, Yinghai Lu wrote:
> David found some resource conflict issue after
> | PCI: Put pci_dev in device tree as early as possible
> | commit 4f535093cf8f6da8cfda7c36c2c1ecd2e9586ee4
>
> and
> | USB: Fix handoff when BIOS disables host PCI device
> | commit: cab928ee1f221c9cc48d6615070fefe2e444384a
>
> for usb qirks for hotplug path.
>
> After checking pci_fixup_device() with pci_fixup_final,
> now we have different path for boot path and hotadd path.
>
> Boot path: because pci_apply_fix_final_quirks is not set yet,
> so pci_fixup_device(pci_fixup_final) will be skipped
> from pci_device_add().
> And later pci_apply_final_quirks will be called for all
> pci devices via fs_initcall.
> That is after pci_assign_unassign resource.
> In that case quirk could use bars with problem.
>
> Hotadd path: pci_fixup_device(pci_fixup_final) will be executed
> via pci_device_add(), and that is too early for hotplug
> path, as pci bar for hot add devices is not assigned yet
> after commit 4f535093.
>
> So we need to move down that for hotplug path, call that in
> pci_bus_add_devices instead, as at that time just before
> drivers get attached.
> And that is simliar calling place for pci_device_add before
> commit 4f535093 is applied.
>
> We should apply this fix for v3.9, but is too late now.
> so get it into v3.10 and could get into v3.9 stable instead.
>
> Reported-by: David Bulkow <David.Bulkow@xxxxxxxxxxx>
> Tested-by: David Bulkow <David.Bulkow@xxxxxxxxxxx>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
I applied the following slightly tweaked patch to for-linus and will
ask Linus to pull it for v3.10. Let me know if it looks OK.
Bjorn
commit a939563f3fd9cd6226c7fb7135d0b93507c53888
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Tue May 7 14:35:44 2013 -0600
PCI: Delay final fixups until resources are assigned
Commit 4f535093cf "PCI: Put pci_dev in device tree as early as possible"
moved final fixups from pci_bus_add_device() to pci_device_add(). But
pci_device_add() happens before resource assignment, so BARs may not be
valid yet.
Typical flow for hot-add:
pciehp_configure_device
pci_scan_slot
pci_scan_single_device
pci_device_add
pci_fixup_device(pci_fixup_final, dev) # previous location
# resource assignment happens here
pci_bus_add_devices
pci_bus_add_device
pci_fixup_device(pci_fixup_final, dev) # new location
[bhelgaas: changelog, move fixups to pci_bus_add_device()]
Reference: https://lkml.kernel.org/r/20130415182614.GB9224@xanatos
Reported-by: David Bulkow <David.Bulkow@xxxxxxxxxxx>
Tested-by: David Bulkow <David.Bulkow@xxxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # v3.9+
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 748f8f3..32e66a6 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -174,6 +174,7 @@ int pci_bus_add_device(struct pci_dev *dev)
* Can not put in pci_device_add yet because resources
* are not assigned yet for some devices.
*/
+ pci_fixup_device(pci_fixup_final, dev);
pci_create_sysfs_dev_files(dev);
dev->match_driver = true;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 43ece5d..67cd045 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1341,7 +1341,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
list_add_tail(&dev->bus_list, &bus->devices);
up_write(&pci_bus_sem);
- pci_fixup_device(pci_fixup_final, dev);
ret = pcibios_add_device(dev);
WARN_ON(ret < 0);
--
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