linux/drivers/pci
Yinghai Lu 93d2175d3d PCI: Clear bridge resource flags if requested size is 0
During pci remove/rescan testing found:

  pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
  pci 0000:c0:03.0:   bridge window [io  0x1000-0x0fff]
  pci 0000:c0:03.0:   bridge window [mem 0xf0000000-0xf00fffff]
  pci 0000:c0:03.0:   bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
  pci 0000:c0:03.0: device not available (can't reserve [io  0x1000-0x0fff])
  pci 0000:c0:03.0: Error enabling bridge (-22), continuing
  pci 0000:c0:03.0: enabling bus mastering
  pci 0000:c0:03.0: setting latency timer to 64
  pcieport 0000:c0:03.0: device not available (can't reserve [io  0x1000-0x0fff])
  pcieport: probe of 0000:c0:03.0 failed with error -22

This bug was caused by commit c8adf9a3e8 ("PCI: pre-allocate
additional resources to devices only after successful allocation of
essential resources.")

After that commit, pci_hotplug_io_size is changed to additional_io_size
from minium size.  So it will not go through resource_size(res) != 0
path, and will not be reset.

The root cause is: pci_bridge_check_ranges will set RESOURCE_IO flag for
pci bridge, and later if children do not need IO resource.  those bridge
resources will not need to be allocated.  but flags is still there.
that will confuse the the pci_enable_bridges later.

related code:

   static void assign_requested_resources_sorted(struct resource_list *head,
                                    struct resource_list_x *fail_head)
   {
           struct resource *res;
           struct resource_list *list;
           int idx;

           for (list = head->next; list; list = list->next) {
                   res = list->res;
                   idx = res - &list->dev->resource[0];
                   if (resource_size(res) && pci_assign_resource(list->dev, idx)) {
   ...
                           reset_resource(res);
                   }
           }
   }

At last, We have to clear the flags in pbus_size_mem/io when requested
size == 0 and !add_head.  becasue this case it will not go through
adjust_resources_sorted().

Just make size1 = size0 when !add_head. it will make flags get cleared.

At the same time when requested size == 0, add_size != 0, will still
have in head and add_list.  because we do not clear the flags for it.

After this, we will get right result:

  pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
  pci 0000:c0:03.0:   bridge window [io  disabled]
  pci 0000:c0:03.0:   bridge window [mem 0xf0000000-0xf00fffff]
  pci 0000:c0:03.0:   bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
  pci 0000:c0:03.0: enabling bus mastering
  pci 0000:c0:03.0: setting latency timer to 64
  pcieport 0000:c0:03.0: setting latency timer to 64
  pcieport 0000:c0:03.0: irq 160 for MSI/MSI-X
  pcieport 0000:c0:03.0: Signaling PME through PCIe PME interrupt
  pci 0000:c4:00.0: Signaling PME through PCIe PME interrupt
  pcie_pme 0000:c0:03.0:pcie01: service driver pcie_pme loaded
  aer 0000:c0:03.0:pcie02: service driver aer loaded
  pciehp 0000:c0:03.0:pcie04: Hotplug Controller:

v3: more simple fix. also fix one typo in pbus_size_mem

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-16 18:33:35 -07:00
..
hotplug Fix common misspellings 2011-03-31 11:26:23 -03:00
pcie Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2011-03-25 21:01:43 -07:00
.gitignore
access.c PCI: output FW warning in pci_read/write_vpd 2010-05-18 15:00:25 -07:00
bus.c Revert "PCI: allocate bus resources from the top down" 2010-12-17 10:00:54 -08:00
dmar.c drivers: Final irq namespace conversion 2011-03-29 14:48:19 +02:00
hotplug-pci.c
hotplug.c
htirq.c drivers: Final irq namespace conversion 2011-03-29 14:48:19 +02:00
intel-iommu.c Merge git://git.infradead.org/iommu-2.6 2011-04-21 09:56:35 -07:00
intr_remapping.c Fix common misspellings 2011-03-31 11:26:23 -03:00
intr_remapping.h
ioapic.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
iov.c PCI: fix pci_resource_alignment prototype 2010-09-09 13:41:25 -07:00
iova.c Fix common misspellings 2011-03-31 11:26:23 -03:00
irq.c
Kconfig PCI: pci-label: Fix build failure when CONFIG_NLS is set to 'm' by allmodconfig 2011-04-12 08:39:02 -07:00
Makefile PCI: pci-label: Fix build failure when CONFIG_NLS is set to 'm' by allmodconfig 2011-04-12 08:39:02 -07:00
msi.c drivers: Final irq namespace conversion 2011-03-29 14:48:19 +02:00
msi.h PCI: MSI: Move MSI-X entry definition to pci_regs.h 2010-12-23 12:53:07 -08:00
pci-acpi.c ACPI: Remove the wakeup.run_wake_count device field 2011-02-24 19:58:53 +01:00
pci-driver.c PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS 2011-04-11 22:54:42 +02:00
pci-label.c PCI: label: remove #include of ACPI header to avoid warnings 2011-03-16 10:24:34 -07:00
pci-stub.c PCI: pci-stub: ignore zero-length id parameters 2010-12-23 12:53:52 -08:00
pci-sysfs.c Fix common misspellings 2011-03-31 11:26:23 -03:00
pci.c PCI: PCIe links may not get configured for ASPM under POWERSAVE mode 2011-03-21 09:40:43 -07:00
pci.h PCI: Export ACPI _DSM provided firmware instance number and string name to sysfs 2011-03-04 10:41:56 -08:00
probe.c PCI: Avoid potential NULL pointer dereference in pci_scan_bridge 2011-02-08 13:08:05 -08:00
proc.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
quirks.c Fix common misspellings 2011-03-31 11:26:23 -03:00
remove.c
rom.c
search.c PCI: use for_each_pci_dev() 2010-07-30 09:47:22 -07:00
setup-bus.c PCI: Clear bridge resource flags if requested size is 0 2011-05-16 18:33:35 -07:00
setup-irq.c PCI: use for_each_pci_dev() 2010-07-30 09:47:22 -07:00
setup-res.c PCI: fix message typo 2010-10-17 20:03:05 -07:00
slot.c PCI: bus speed strings should be const 2010-08-31 15:28:00 -07:00
syscall.c
vpd.c pci: Add helper to search for VPD keywords 2010-02-28 00:43:33 -08:00
xen-pcifront.c pci/xen: Cleanup: convert int** to int[] 2011-02-18 12:41:49 -05:00