Commit graph

34036 commits

Author SHA1 Message Date
David Woodhouse
956e944c76 [MTD NAND] Allow override of page read and write functions.
- allow high-level nand_write_page() function to be overridden
- likewise low-level write_page_raw() and read_page_raw() functions
- Clean up the abuse of chip->ecc.{write,read}_page() with MTD_OOB_RAW

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:12:39 +01:00
David Woodhouse
4bf63fcb83 [MTD NAND] Allocate chip->buffers separately to allow it to be overridden
In particular, the board driver might need it to be DMAable.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:08:04 +01:00
David Woodhouse
3b85c3211e [MTD NAND] Split nand_scan() into two parts; allow board driver to intervene
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:06:53 +01:00
David Woodhouse
4b648b0253 [MTD NAND] Export nand_wait_ready() for use by board drivers
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:05:24 +01:00
David Woodhouse
08d3ad6a51 [MTD] Whitespace cleanup in SSFDC driver.
Says akpm: ' - search for "( " and " )", fix.'

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-23 16:20:48 +01:00
David Woodhouse
9a05eded5d [MTD] SSFDC translation layer minor cleanup
Don't include <linux/config.h>.
Don't say 'MB' where you mean 'MiB'.
Don't allocate 512 bytes on the stack.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-23 10:56:24 +01:00
David Woodhouse
892e4fba1c [MTD] Fix dependencies with CONFIG_MTD=m
CMDLINEPARTS shouldn't be selectable, and neither should SSFDC, which
can be a tristate anyway.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-23 10:24:36 +01:00
David Woodhouse
734a56285d Remove accidentally-added include/linux/utsrelease.h
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 18:41:20 +01:00
David Woodhouse
e4e3295f0c Revert "[MTD] blkdev helper code: fix printk format warning"
This reverts commit 668040fcd1.

The 'flags' field of the struct request is 'unsigned long'. Quite
how Randy came to see 'long int format, different type arg' I don't
know, but it doesn't seem to be the case any more.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 11:05:42 +01:00
Claudio Lanconelli
51197abf29 [MTD] Add SSFDC (SmartMedia) read-only translation layer
Signed-off-by: Claudio Lanconelli <lanconelli.claudio@eptar.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 11:01:37 +01:00
Jiri Slaby
98aacdfde0 [MTD] pmc551 pci cleanup
Use pci_resource_start for getting start of regions and pci_iomap to not
doing this directly by using dev->resource... (Thanks to Rolf Eike Beer)

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:34:15 +01:00
Jiri Slaby
7fefb924d7 [MTD] pmc551 use kzalloc
Use kzalloc instad of kmalloc+memset(0).

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:33:52 +01:00
Jiri Slaby
cdf0a7d169 [MTD] pmc551 whitespace cleanup
Spaces were used for indent, there was more than 80 columns per line. Get
rid of that stuff.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:33:31 +01:00
Lennert Buytenhek
e417fcfb85 [MTD] Remove iq80310 map driver
The iq80310 mtd map driver depends on ARCH_IQ80310, which isn't
defined anywhere in the tree (as we don't have 80310 support), and
furthermore, everything the driver does can be done with physmap
instead.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:31:01 +01:00
Frank Haverkamp
6a545a0d60 [MTD NAND] Fix in typo ndfc.c causing wrong ECC layout
Due to this typo, a wrong ECC layout table is chosen.

Signed-off-by: Frank Haverkamp <haver@vnet.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:30:25 +01:00
Lennert Buytenhek
17c2dae3aa [MTD] physmap: add power management support
Implement PM handling for physmap.  Idea from Steven Scholz, patch
by David Anders.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:26:56 +01:00
Amol Lad
25f0c659fe ioremap balanced with iounmap for drivers/mtd subsystem
ioremap must be balanced by an iounmap and failing to do so can result
in a memory leak.

Tested (compilation only) with:
- allmodconfig
- Modifying drivers/mtd/maps/Kconfig and drivers/mtd/nand/Kconfig to
make sure that the changed file is compiling without warning

Signed-off-by: Amol Lad <amol@verismonetworks.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:24:31 +01:00
Alan Cox
dd8e9ed6ed [MTD] Switch to pci_get_device and do ref counting
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:19:20 +01:00
Randy Dunlap
668040fcd1 [MTD] blkdev helper code: fix printk format warning
Fix printk format warning(s):
drivers/mtd/mtd_blkdevs.c:72: warning: long int format, different type arg (arg 2)

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:17:28 +01:00
Brian Walsh
f40a6f1cc7 [MTD] Fix ixp4xx partition parsing.
If the amount of flash is not divisible by 2 then the mask in
parse_mtd_partitions would fail to work as designed.  Passing in the base
address corrects this problem.

Signed-off-by: Brian Walsh <brian@walsh.ws>
Cc: Deepak Sanexa <dsanexa@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:16:16 +01:00
Michal Piotrowski
f2dd117fa5 [JFFS2] Remove unneeded ifdefs from jffs2_fs_i.h
We certainly don't need the check for Linux version > 2.5.2, and in fact
we can also live without the __ECOS check, since we can just add it back
in the eCos git tree which is automatically derived from the Linux fs/jffs2
subdirectory in the upstream git tree.

Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:13:46 +01:00
Michal Piotrowski
cbc88ba83f [MTD NAND] Remove old code in au1550nd.c
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:09:44 +01:00
Håvard Skinnemoen
187ef15268 [MTD] Unlock NOR flash automatically where necessary
Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is
always locked after power-up, so all sectors need to be unlocked before it
is usable.

If this flag is set, and the chip provides an unlock() operation,
mtd_add_device will unlock the whole MTD device if it's writeable.  This
means that non-writeable partitions will stay locked.

Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work
as expected.

Signed-off-by: Håvard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-22 10:07:08 +01:00
Linus Torvalds
e478bec0ba Linux v2.6.18. Arrr!
Ahoy, all land-lubbers, test me out right smartly!

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 20:42:06 -07:00
Linus Torvalds
3752aee965 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [IPV4] fib_trie: missing ntohl() when calling fib_semantic_match()
  [NETFILTER]: xt_quota: add missing module aliases
  [ATM]: [he] don't hold the device lock when upcalling
2006-09-19 20:36:22 -07:00
Al Viro
888454c57a [IPV4] fib_trie: missing ntohl() when calling fib_semantic_match()
fib_trie.c::check_leaf() passes host-endian where fib_semantic_match()
expects (and stores into) net-endian.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-19 13:42:46 -07:00
Patrick McHardy
b22b9004f2 [NETFILTER]: xt_quota: add missing module aliases
Add missing aliases for ipt_quota and ip6t_quota to make autoload
work.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-19 13:00:57 -07:00
Chas Williams
7f81dc0097 [ATM]: [he] don't hold the device lock when upcalling
This can create a deadlock/lock ordering problem with other layers
that want to use the transmit (or other) path of the card at that
time.

Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-19 12:59:11 -07:00
Linus Torvalds
4ed4b54752 Merge branch 'fixes' of git://git.linux-nfs.org/pub/linux/nfs-2.6
* 'fixes' of git://git.linux-nfs.org/pub/linux/nfs-2.6:
  NFS: Fix nfs_page use after free issues in fs/nfs/write.c
  NFSv4: Fix incorrect semaphore release in _nfs4_do_open()
  NFS: Fix Oopsable condition in nfs_readpage_sync()
2006-09-19 09:46:53 -07:00
Trond Myklebust
5c2d97cb31 NFS: Fix nfs_page use after free issues in fs/nfs/write.c
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-19 11:59:10 -04:00
Trond Myklebust
76723de0cf NFSv4: Fix incorrect semaphore release in _nfs4_do_open()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-19 11:54:53 -04:00
Trond Myklebust
7a52411107 NFS: Fix Oopsable condition in nfs_readpage_sync()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-19 11:54:39 -04:00
Linus Torvalds
79e453d49b Revert mmiocfg heuristics and blacklist changes
This reverts commits 11012d419c and
40dd2d20f2, which allowed us to use the
MMIO accesses for PCI config cycles even without the area being marked
reserved in the e820 memory tables.

Those changes were needed for EFI-environment Intel macs, but broke some
newer Intel 965 boards, so for now it's better to revert to our old
2.6.17 behaviour and at least avoid introducing any new breakage.

Andi Kleen has a set of patches that work with both EFI and the broken
Intel 965 boards, which will be applied once they get wider testing.

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Edgar Hucek <hostmaster@ed-soft.at>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 08:15:22 -07:00
Linus Torvalds
ab5cfd2aa3 Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6:
  [MTD] Use SEEK_{SET,CUR,END} instead of hardcoded values in mtdchar lseek()
  MTD: Fix bug in fixup_convert_atmel_pri
  [JFFS2][SUMMARY] Fix a summary collecting bug.
  [PATCH] [MTD] DEVICES: Fill more device IDs in the structure of m25p80
  MTD: Add lock/unlock operations for Atmel AT49BV6416
  MTD: Convert Atmel PRI information to AMD format
  fs/jffs2/xattr.c: remove dead code
  [PATCH] [MTD] Maps: Add dependency on alternate probe methods to physmap
  [PATCH] MTD: Add Macronix MX29F040 to JEDEC
  [MTD] Fixes of performance and stability issues in CFI driver.
  block2mtd.c: Make kernel boot command line arguments work (try 4)
  [MTD NAND] Fix lookup error in nand_get_flash_type()
  remove #error on !PCI from pmc551.c
  MTD: [NAND] Fix the sharpsl driver after breakage from a core conversion
  [MTD] NAND: OOB buffer offset fixups
  make fs/jffs2/nodelist.c:jffs2_obsolete_node_frag() static
  [PATCH] [MTD] NAND: fix dead URL in Kconfig
2006-09-19 08:01:58 -07:00
Dave Kleikamp
833f73299f [PATCH] EXT2: Remove superblock lock contention in ext2_statfs
Fix a performance degradation introduced in 2.6.17.  (30% degradation
running dbench with 16 threads)

Commit 21730eed11, which claims to make
EXT2_DEBUG work again, moves the taking of the kernel lock out of
debug-only code in ext2_count_free_inodes and ext2_count_free_blocks and
into ext2_statfs.

The same problem was fixed in ext3 by removing the lock completely (commit
5b11687924)

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 07:59:59 -07:00
Matthew Wilcox
ac7fb273ca [PATCH] headers_check: Clean up asm-parisc/page.h for user headers
Remove definitions of PAGE_* from the user view
Delete unnecessary comments referring to the size of pages
Only include <asm-generic> if we're in __KERNEL__

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 07:59:59 -07:00
Geert Uytterhoeven
020d8c063b [PATCH] Fix 'make headers_check' on ia64
Fix 'make headers_check' on m68k

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 07:59:59 -07:00
David Woodhouse
271fc18eea [PATCH] Add headers_check' target to output of 'make help'
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 07:59:59 -07:00
Ingo Molnar
86998aa653 [PATCH] genirq core: fix handle_level_irq()
while porting the -rt tree to 2.6.18-rc7 i noticed the following
screaming-IRQ scenario on an SMP system:

 2274  0Dn.:1 0.001ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.010ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.020ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.029ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.039ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.048ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.058ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.068ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.077ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.087ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)
 2274  0Dn.:1 0.097ms: do_IRQ+0xc/0x103  <= (ret_from_intr+0x0/0xf)

as it turns out, the bug is caused by handle_level_irq(), which if it
races with another CPU already handling this IRQ, it _unmasks_ the IRQ
line on the way out. This is not how 2.6.17 works, and we introduced
this bug in one of the early genirq cleanups right before it went into
-mm. (the bug was not in the genirq patchset for a long time, and we
didnt notice the bug due to the lack of -rt rebase to the new genirq
code. -rt, and hardirq-preemption in particular opens up such races much
wider than anything else.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-19 07:57:20 -07:00
Linus Torvalds
47a5c6fa0e x86: save/restore eflags in context switch
(And reset it on new thread creation)

It turns out that eflags is important to save and restore not just
because of iopl, but due to the magic bits like the NT bit, which we
don't want leaking between different threads.

Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-18 16:20:40 -07:00
Linus Torvalds
1d19f176a2 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [ATM] CLIP: Do not refer freed skbuff in clip_mkip().
  [NET]: Drop tx lock in dev_watchdog_up
  [PACKET]: Don't truncate non-linear skbs with mmaped IO
  [NET]: Mark frame diverter for future removal.
  [NETFILTER]: Add secmark headers to header-y
  [ATM]: linux-atm-general mailing list is subscribers only
  [ATM]: [he] when transmit fails, unmap the dma regions
  [TCP] tcp-lp: update information to MAINTAINERS
  [TCP] tcp-lp: bug fix for oops in 2.6.18-rc6
  [BRIDGE]: random extra bytes on STP TCN packet
  [IPV6]: Accept -1 for IPV6_TCLASS
  [IPV6]: Fix tclass setting for raw sockets.
  [IPVS]: remove the debug option go ip_vs_ftp
  [IPVS]: Make sure ip_vs_ftp ports are valid
  [IPVS]: auto-help for ip_vs_ftp
  [IPVS]: Document the ports option to ip_vs_ftp in kernel-parameters.txt
  [TCP]: Turn ABC off.
  [NEIGH]: neigh_table_clear() doesn't free stats
2006-09-18 16:16:05 -07:00
Linus Torvalds
20bf94e266 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC]: Fix regression in sys_getdomainname()
  [OPENPROMIO]: Handle current_node being NULL correctly.
2006-09-18 16:15:40 -07:00
Linus Torvalds
77e2782f9b Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 3815/1: headers_install support for ARM
  [ARM] 3794/1: S3C24XX: do not defined set_irq_wake when no CONFIG_PM
  [ARM] 3793/1: S3C2412: fix wrong serial info struct
  [ARM] 3780/1: Fix iop321 cpuid
  [ARM] 3786/1: pnx4008: update defconfig
  [ARM] 3785/1: S3C2412: Fix idle code as default uses wrong clocks
  [ARM] 3784/1: S3C2413: fix config for MACH_S3C2413/MACH_SMDK2413
2006-09-18 16:15:16 -07:00
Ralph Siemsen
e40b1074af [ARM] 3815/1: headers_install support for ARM
Move kernel-only #includes into #ifdef __KERNEL__, so that
headers_install target can be used on ARM.

Signed-off-by: Ralph Siemsen <ralphs@netwinder.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-18 16:28:50 +01:00
Andy Walker
b9c54f91a4 [SPARC]: Fix regression in sys_getdomainname()
This patch corrects the buffer length checking in the
sys_getdomainname() implementation for sparc/sparc64.

Signed-off-by: Andy Walker <andy@puszczka.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-18 07:11:36 -07:00
YOSHIFUJI Hideaki
fe26109a9d [ATM] CLIP: Do not refer freed skbuff in clip_mkip().
In clip_mkip(), skb->dev is dereferenced after clip_push(),
which frees up skb.

Advisory: AD_LAB-06009 (<adlab@venustech.com.cn>).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-18 06:37:58 -07:00
Ben Dooks
a9c3685b2f [ARM] 3794/1: S3C24XX: do not defined set_irq_wake when no CONFIG_PM
Patch from Ben Dooks

Do not define set_irq_wake as a real function if
the CONFIG_PM option is not set.

Fixes bug reported by Thomas Gleixner.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-18 13:30:20 +01:00
Ben Dooks
71aa7054d3 [ARM] 3793/1: S3C2412: fix wrong serial info struct
Patch from Ben Dooks

The S3C2440 serial info struct is being passed
through the S3C2412 serial info struct probe
routine.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Glexiner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-18 13:30:17 +01:00
David S. Miller
b9b64e6e89 [OPENPROMIO]: Handle current_node being NULL correctly.
If the user tries to traverse to the next node of the
last node, we get NULL in current_node and a zero phandle
returned.  That's fine, but if the user tries to obtain
properties in that state, we try to dereference a NULL
pointer in the downcall to the of_*() routines.

So protect against that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-18 01:47:13 -07:00
Herbert Xu
d7811e623d [NET]: Drop tx lock in dev_watchdog_up
Fix lockdep warning with GRE, iptables and Speedtouch ADSL, PPP over ATM.

On Sat, Sep 02, 2006 at 08:39:28PM +0000, Krzysztof Halasa wrote:
> 
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> -------------------------------------------------------
> swapper/0 is trying to acquire lock:
>  (&dev->queue_lock){-+..}, at: [<c02c8c46>] dev_queue_xmit+0x56/0x290
> 
> but task is already holding lock:
>  (&dev->_xmit_lock){-+..}, at: [<c02c8e14>] dev_queue_xmit+0x224/0x290
> 
> which lock already depends on the new lock.

This turns out to be a genuine bug.  The queue lock and xmit lock are
intentionally taken out of order.  Two things are supposed to prevent
dead-locks from occuring:

1) When we hold the queue_lock we're supposed to only do try_lock on the
tx_lock.

2) We always drop the queue_lock after taking the tx_lock and before doing
anything else.

> 
> the existing dependency chain (in reverse order) is:
> 
> -> #1 (&dev->_xmit_lock){-+..}:
>        [<c012e7b6>] lock_acquire+0x76/0xa0
>        [<c0336241>] _spin_lock_bh+0x31/0x40
>        [<c02d25a9>] dev_activate+0x69/0x120

This path obviously breaks assumption 1) and therefore can lead to ABBA
dead-locks.

I've looked at the history and there seems to be no reason for the lock
to be held at all in dev_watchdog_up.  The lock appeared in day one and
even there it was unnecessary.  In fact, people added __dev_watchdog_up
precisely in order to get around the tx lock there.

The function dev_watchdog_up is already serialised by rtnl_lock since
its only caller dev_activate is always called under it.

So here is a simple patch to remove the tx lock from dev_watchdog_up.
In 2.6.19 we can eliminate the unnecessary __dev_watchdog_up and
replace it with dev_watchdog_up.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-18 00:22:30 -07:00