Revision 93d2175d3d31f11ba04fcfa0e9a496a1b4bc8b34 authored by Yinghai Lu on 14 May 2011, 01:06:17 UTC, committed by Linus Torvalds on 17 May 2011, 01:33:35 UTC
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 c8adf9a3e873 ("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>
1 parent df8d06a
Raw File
Kconfig
#
# Configuration for initramfs
#

config INITRAMFS_SOURCE
	string "Initramfs source file(s)"
	default ""
	help
	  This can be either a single cpio archive with a .cpio suffix or a
	  space-separated list of directories and files for building the
	  initramfs image.  A cpio archive should contain a filesystem archive
	  to be used as an initramfs image.  Directories should contain a
	  filesystem layout to be included in the initramfs image.  Files
	  should contain entries according to the format described by the
	  "usr/gen_init_cpio" program in the kernel tree.

	  When multiple directories and files are specified then the
	  initramfs image will be the aggregate of all of them.

	  See <file:Documentation/early-userspace/README> for more details.

	  If you are not sure, leave it blank.

config INITRAMFS_ROOT_UID
	int "User ID to map to 0 (user root)"
	depends on INITRAMFS_SOURCE!=""
	default "0"
	help
	  This setting is only meaningful if the INITRAMFS_SOURCE is
	  contains a directory.  Setting this user ID (UID) to something
	  other than "0" will cause all files owned by that UID to be
	  owned by user root in the initial ramdisk image.

	  If you are not sure, leave it set to "0".

config INITRAMFS_ROOT_GID
	int "Group ID to map to 0 (group root)"
	depends on INITRAMFS_SOURCE!=""
	default "0"
	help
	  This setting is only meaningful if the INITRAMFS_SOURCE is
	  contains a directory.  Setting this group ID (GID) to something
	  other than "0" will cause all files owned by that GID to be
	  owned by group root in the initial ramdisk image.

	  If you are not sure, leave it set to "0".

config RD_GZIP
	bool "Support initial ramdisks compressed using gzip" if EXPERT
	default y
	depends on BLK_DEV_INITRD
	select DECOMPRESS_GZIP
	help
	  Support loading of a gzip encoded initial ramdisk or cpio buffer.
	  If unsure, say Y.

config RD_BZIP2
	bool "Support initial ramdisks compressed using bzip2" if EXPERT
	default !EXPERT
	depends on BLK_DEV_INITRD
	select DECOMPRESS_BZIP2
	help
	  Support loading of a bzip2 encoded initial ramdisk or cpio buffer
	  If unsure, say N.

config RD_LZMA
	bool "Support initial ramdisks compressed using LZMA" if EXPERT
	default !EXPERT
	depends on BLK_DEV_INITRD
	select DECOMPRESS_LZMA
	help
	  Support loading of a LZMA encoded initial ramdisk or cpio buffer
	  If unsure, say N.

config RD_XZ
	bool "Support initial ramdisks compressed using XZ" if EXPERT
	default !EXPERT
	depends on BLK_DEV_INITRD
	select DECOMPRESS_XZ
	help
	  Support loading of a XZ encoded initial ramdisk or cpio buffer.
	  If unsure, say N.

config RD_LZO
	bool "Support initial ramdisks compressed using LZO" if EXPERT
	default !EXPERT
	depends on BLK_DEV_INITRD
	select DECOMPRESS_LZO
	help
	  Support loading of a LZO encoded initial ramdisk or cpio buffer
	  If unsure, say N.

choice
	prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!=""
	help
	  This option decides by which algorithm the builtin initramfs
	  will be compressed.  Several compression algorithms are
	  available, which differ in efficiency, compression and
	  decompression speed.  Compression speed is only relevant
	  when building a kernel.  Decompression speed is relevant at
	  each boot.

	  If you have any problems with bzip2 or LZMA compressed
	  initramfs, mail me (Alain Knaff) <alain@knaff.lu>.

	  High compression options are mostly useful for users who are
	  low on RAM, since it reduces the memory consumption during
	  boot.

	  If in doubt, select 'gzip'

config INITRAMFS_COMPRESSION_NONE
	bool "None"
	help
	  Do not compress the built-in initramfs at all. This may
	  sound wasteful in space, but, you should be aware that the
	  built-in initramfs will be compressed at a later stage
	  anyways along with the rest of the kernel, on those
	  architectures that support this.
	  However, not compressing the initramfs may lead to slightly
	  higher memory consumption during a short time at boot, while
	  both the cpio image and the unpacked filesystem image will
	  be present in memory simultaneously

config INITRAMFS_COMPRESSION_GZIP
	bool "Gzip"
	depends on RD_GZIP
	help
	  The old and tried gzip compression. It provides a good balance
	  between compression ratio and decompression speed.

config INITRAMFS_COMPRESSION_BZIP2
	bool "Bzip2"
	depends on RD_BZIP2
	help
	  Its compression ratio and speed is intermediate.
	  Decompression speed is slowest among the four.  The initramfs
	  size is about 10% smaller with bzip2, in comparison to gzip.
	  Bzip2 uses a large amount of memory. For modern kernels you
	  will need at least 8MB RAM or more for booting.

config INITRAMFS_COMPRESSION_LZMA
	bool "LZMA"
	depends on RD_LZMA
	help
	  The most recent compression algorithm.
	  Its ratio is best, decompression speed is between the other
	  three. Compression is slowest. The initramfs size is about 33%
	  smaller with LZMA in comparison to gzip.

config INITRAMFS_COMPRESSION_XZ
	bool "XZ"
	depends on RD_XZ
	help
	  XZ uses the LZMA2 algorithm. The initramfs size is about 30%
	  smaller with XZ in comparison to gzip. Decompression speed
	  is better than that of bzip2 but worse than gzip and LZO.
	  Compression is slow.

config INITRAMFS_COMPRESSION_LZO
	bool "LZO"
	depends on RD_LZO
	help
	  Its compression ratio is the poorest among the four. The kernel
	  size is about 10% bigger than gzip; however its speed
	  (both compression and decompression) is the fastest.

endchoice
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