Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

During initialization we would not have received any beacons
so skip processing reg beacon hints, also adds a check to
reg_is_world_roaming() for last_request before accessing its
fields.

This should fix this:

BUG: unable to handle kernel NULL pointer dereference at

IP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295

*pdpt = 0000000008bf1001 *pde = 0000000000000000
Oops: 0000 [#1]
last sysfs file: /sys/class/backlight/eeepc/brightness
Modules linked in: ath5k(+) mac80211 led_class cfg80211
go_bit cfbcopyarea cfbimgblt cfbfillrect ipv6
ydev usual_tables(P) snd_hda_codec_realtek snd_hda_intel
nd_hwdep uhci_hcd snd_pcm_oss snd_mixer_oss i2c_i801
e serio_raw i2c_core pcspkr atl2 snd_pcm intel_agp
re agpgart eeepc_laptop snd_page_alloc ac video backlight
rfkill button processor evdev thermal fan ata_generic

Pid: 2909, comm: modprobe Tainted: Pc #112) 701
EIP: 0060:[<e0171332>] EFLAGS: 00010246 CPU: 0
EIP is at wiphy_update_regulatory+0x20f/0x295 [cfg80211]
EAX: 00000000 EBX: c5da0000 ECX: 00000000 EDX: c5da0060
ESI: 0000001a EDI: c5da0060 EBP: df3bdd70 ESP: df3bdd40
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process modprobe (pid: 2909, ti=df3bc000 task=c5d030000)
Stack:
 df3bdd90 c5da0060 c04277e0 00000001 00000044 c04277e402
 00000002 c5da0000 0000001a c5da0060 df3bdda8 e01706a2 02
 00000282 000080d0 00000068 c5d53500 00000080 0000028240
Call Trace:
 [<e01706a2>] ? wiphy_register+0x122/0x1b7 [cfg80211]
 [<e0328e02>] ? ieee80211_register_hw+0xd8/0x346
 [<e06a7c9f>] ? ath5k_hw_set_bssid_mask+0x71/0x78 [ath5k]
 [<e06b0c52>] ? ath5k_pci_probe+0xa5c/0xd0a [ath5k]
 [<c01a6037>] ? sysfs_find_dirent+0x16/0x27
 [<c01fec95>] ? local_pci_probe+0xe/0x10
 [<c01ff526>] ? pci_device_probe+0x48/0x66
 [<c024c9fd>] ? driver_probe_device+0x7f/0xf2
 [<c024cab3>] ? __driver_attach+0x43/0x5f
 [<c024c0af>] ? bus_for_each_dev+0x39/0x5a
 [<c024c8d0>] ? driver_attach+0x14/0x16
 [<c024ca70>] ? __driver_attach+0x0/0x5f
 [<c024c5b3>] ? bus_add_driver+0xd7/0x1e7
 [<c024ccb9>] ? driver_register+0x7b/0xd7
 [<c01ff827>] ? __pci_register_driver+0x32/0x85
 [<e00a8018>] ? init_ath5k_pci+0x18/0x30 [ath5k]
 [<c0101131>] ? _stext+0x49/0x10b
 [<e00a8000>] ? init_ath5k_pci+0x0/0x30 [ath5k]
 [<c012f452>] ? __blocking_notifier_call_chain+0x40/0x4c
 [<c013a714>] ? sys_init_module+0x87/0x18b
 [<c0102804>] ? sysenter_do_call+0x12/0x22
Code: b8 da 17 e0 83 c0 04 e8 92 f9 ff ff 84 c0 75 2a 8b
85 c0 74 0c 83 c0 04 e8 7c f9 ff ff 84 c0 75 14 a1 bc da
4 03 74 66 8b 4d d4 80 79 08 00 74 5d a1 e0 d2 17 e0 48
EIP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295
SP 0068:df3bdd40
CR2: 0000000000000004
---[ end trace 830f2dd2a95fd1a8 ]---

This issue is hard to reproduce, but it was noticed and discussed on
this thread:

http://marc.info/?t=123938022700005&r=1&w=2

Cc: stable@kernel.org
Reported-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We forgot to lock using the cfg80211_mutex in
wiphy_apply_custom_regulatory(). Without the lock
there is possible race between processing a reply from CRDA
and a driver calling wiphy_apply_custom_regulatory(). During
the processing of the reply from CRDA we free last_request and
wiphy_apply_custom_regulatory() eventually accesses an
element from last_request in the through freq_reg_info_regd().

This is very difficult to reproduce (I haven't), it takes us
3 hours and you need to be banging hard, but the race is obvious
by looking at the code.

This should only affect those who use this caller, which currently
is ath5k, ath9k, and ar9170.

EIP: 0060:[<f8ebec50>] EFLAGS: 00210282 CPU: 1
EIP is at freq_reg_info_regd+0x24/0x121 [cfg80211]
EAX: 00000000 EBX: f7ca0060 ECX: f5183d94 EDX: 0024cde0
ESI: f8f56edc EDI: 00000000 EBP: 00000000 ESP: f5183d44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process modprobe (pid: 14617, ti=f5182000 task=f3934d10 task.ti=f5182000)
Stack: c0505300 f7ca0ab4 f5183d94 0024cde0 f8f403a6 f8f63160 f7ca0060 00000000
00000000 f8ebedf8 f5183d90 f8f56edc 00000000 00000004 00000f40 f8f56edc
f7ca0060 f7ca1234 00000000 00000000 00000000 f7ca14f0 f7ca0ab4 f7ca1289
Call Trace:
[<f8ebedf8>] wiphy_apply_custom_regulatory+0x8f/0x122 [cfg80211]
[<f8f3f798>] ath_attach+0x707/0x9e6 [ath9k]
[<f8f45e46>] ath_pci_probe+0x18d/0x29a [ath9k]
[<c023c7ba>] pci_device_probe+0xa3/0xe4
[<c02a860b>] really_probe+0xd7/0x1de
[<c02a87e7>] __driver_attach+0x37/0x55
[<c02a7eed>] bus_for_each_dev+0x31/0x57
[<c02a83bd>] driver_attach+0x16/0x18
[<c02a78e6>] bus_add_driver+0xec/0x21b
[<c02a8959>] driver_register+0x85/0xe2
[<c023c9bb>] __pci_register_driver+0x3c/0x69
[<f8e93043>] ath9k_init+0x43/0x68 [ath9k]
[<c010112b>] _stext+0x3b/0x116
[<c014a872>] sys_init_module+0x8a/0x19e
[<c01049ad>] sysenter_do_call+0x12/0x21
[<ffffe430>] 0xffffe430
=======================
Code: 0f 94 c0 c3 31 c0 c3 55 57 56 53 89 c3 83 ec 14 8b 74 24 2c 89 54 24 0c 89 4c 24 08 85 f6 75
06 8b 35 c8 bb ec f8 a1 cc bb ec f8 <8b> 40 04 83 f8 03 74 3a 48 74 37 8b 43 28 85 c0 74 30 89 c6
8b
EIP: [<f8ebec50>] freq_reg_info_regd+0x24/0x121 [cfg80211] SS:ESP 0068:f5183d44

Cc: stable@kernel.org
Reported-by: NNataraj Sadasivam <Nataraj.Sadasivam@Atheros.com>
Reported-by: NVivek Natarajan <Vivek.Natarajan@Atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We need to be symmetrical in what is done when key is set and cleared.
This is important wrt the key flags as they are used during key
clearing and if they are not set when the key is set the key cannot be
cleared completely.

This addresses the many occurences of the WARN found in
iwl_set_tkip_dynamic_key_info() and tracked in
http://www.kerneloops.org/searchweek.php?search=iwl_set_dynamic_key

If calling iwl_set_tkip_dynamic_key_info()/iwl_remove_dynamic_key()
pair a few times in a row will cause that we run out of key space.
This is because the index stored in the key flags is used by
iwl_remove_dynamic_key() to decide if it should remove the key.
Unfortunately the key flags, and hence the key index is currently only
set at the time the key is written to the device (in
iwl_update_tkip_key()) and _not_ in iwl_set_tkip_dynamic_key_info().
Fix this by setting flags in iwl_set_tkip_dynamic_key_info().
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Another bug in the "cfg80211: do not replace BSS structs" patch,
a forgotten length update leads to bogus data being stored and
passed to userspace, often truncated.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The fragmentation threshold is defined to be including the
FCS, and the code that sets the TX_FRAGMENTED flag correctly
accounts for those four bytes. The code that verifies this
doesn't though, which could lead to spurious warnings and
frames being dropped although everything is ok. Correct the
code by accounting for the FCS.

(JWL -- The problem is described here:
 http://article.gmane.org/gmane.linux.kernel.wireless.general/32205 )
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It does not make sense to apply EXPORT_SYMBOL to a static symbol.  Fixes
this build error:

drivers/net/wireless/iwlwifi/iwl3945-base.c:1697: error: __ksymtab_iwl3945_rx_queue_reset causes a section type conflict
Signed-off-by: NAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Doing it in reverse order causes uevent to be sent before
we have a MAC address, which confuses udev.
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 0ba25ff4 ("br2684: convert to
net_device_ops") inadvertently deleted the initialization of the net_dev
pointer in the br2684_dev structure, leading to crashes.  This patch
adds it back.
Reported-by: NMikko Vinni <mmvinni@yahoo.com>
Tested-by: NMikko Vinni <mmvinni@yahoo.com>
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The kernel should only be using the high 16 bits of a kernel
generated priority. Filter priorities in all other cases only
use the upper 16 bits of the u32 'prio' field of 'struct tcf_proto',
but when the kernel generates the priority of a filter is saves all
32 bits which can result in incorrect lookup failures when a filter
needs to be deleted or modified.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We were avoiding calling sg_init* on scatterlists passed
into virtnet_send_command to prevent extraneous end markers.
This caused build warnings for uninitialized variables.
Cleanup the code to create proper scatterlists.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes the cleanup in bond_create nicer :) Also now the forgotten
free_netdev is called.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

virtio_net.h uses the macro ETH_ALEN which is defined in linux/if_ether.h.
Discovered when hacking on virtio-over-pci patches.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

LAN9512 and LAN9514 are USB hubs with an integrated 10/100 ethernet
controller.  Logically this looks like an ethernet controller (similar
to LAN9500) permanently attached to one of the hub's downstream ports.

This patch adds the usb device id of the new ethernet controller to the
smsc95xx driver.  This id is the same in both new devices.
Signed-off-by: NSteve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SMSC LAN9500 has dual purpose GPIO/LED pins, and by default at power-on
these are configured as GPIOs.  This means that if LEDs are fitted they
won't ever light.

This patch sets them to be LED outputs for speed, duplex and
link/activity.
Signed-off-by: NSteve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When netconsole is loaded and a network interface fades away (e.g. on
rmmod $interface_driver_module) the rmmod remains stuck and some locks
are taken that prevent any additional module loading/unloading as well
as interface up/down changes.
In addition kernel logs (and console) get flooded at 10s interval with

[  122.464065] unregister_netdevice: waiting for eth0 to become free. Usage count = 1
[  132.704059] unregister_netdevice: waiting for eth0 to become free. Usage count = 1

This patch lets netconsole take NETDEV_UNREGISTER event into account
and release the affected interface if it was in use.
Signed-off-by: NBruno Prémont <bonbons@linux-vserver.org>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xt_socket can use connection tracking, and checks whether it is a module.
Signed-off-by: NLaszlo Attila Toth <panther@balabit.hu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bond_slave_info_query() should keep a read lock while accessing slave info,
or risk accessing stale data and corruption.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Trivial: fixing gcc 4.4 compiler warning:
drivers/net/cxgb3/t3_hw.c: In function ‘t3_prep_adapter’:
drivers/net/cxgb3/t3_hw.c:3782: warning: suggest parentheses around operand of ‘!’ or change ‘|’ to ‘||’ or ‘!’ to ‘~’
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@mail.by>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When skb_rx_queue_recorded() is true, we dont want to use jash distribution
as the device driver exactly told us which queue was selected at RX time.
jhash makes a statistical shuffle, but this wont work with 8 static inputs.

Later improvements would be to compute reciprocal value of real_num_tx_queues
to avoid a divide here. But this computation should be done once,
when real_num_tx_queues is set. This needs a separate patch, and a new
field in struct net_device.
Reported-by: NAndrew Dickinson <andrew@whydna.net>
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lennert Buytenhek wrote:
> Since 4fb66994 ("net: Optimize memory
> usage when splicing from sockets.") I'm seeing this oops (e.g. in
> 2.6.30-rc3) when splicing from a TCP socket to /dev/null on a driver
> (mv643xx_eth) that uses LRO in the skb mode (lro_receive_skb) rather
> than the frag mode:

My patch incorrectly assumed skb->sk was always valid, but for
"frag_listed" skbs we can only use skb->sk of their parent.
Reported-by: NLennert Buytenhek <buytenh@wantstofly.org>
Debugged-by: NLennert Buytenhek <buytenh@wantstofly.org>
Tested-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On several mv643xx_eth hardware versions, the two 64bit mib counters
for 'good octets received' and 'good octets sent' are actually 32bit
counters, and reading from the upper half of the register has the same
effect as reading from the lower half of the register: an atomic
read-and-clear of the entire 32bit counter value.  This can under heavy
traffic occasionally lead to small numbers being added to the upper
half of the 64bit mib counter even though no 32bit wrap has occured.

Since we poll the mib counters at least every 30 seconds anyway, we
might as well just skip the reads of the upper halves of the hardware
counters without breaking the stats, which this patch does.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Cc: stable@kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, when OOM occurs during rx ring refill, mv643xx_eth will get
into an infinite loop, due to the refill function setting the OOM bit
but not clearing the 'rx refill needed' bit for this queue, while the
calling function (the NAPI poll handler) will call the refill function
in a loop until the 'rx refill needed' bit goes off, without checking
the OOM bit.

This patch fixes this by checking the OOM bit in the NAPI poll handler
before attempting to do rx refill.  This means that once OOM occurs,
we won't try to do any memory allocations again until the next invocation
of the poll handler.

While we're at it, change the OOM flag to be a single bit instead of
one bit per receive queue since OOM is a system state rather than a
per-queue state, and cancel the OOM timer on entry to the NAPI poll
handler if it's running to prevent it from firing when we've already
come out of OOM.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Cc: stable@kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In "mac80211: correct wext transmit power handler"
I fixed the wext handler, but forgot to make the default of the
user_power_level -1 (aka "auto"), so that now the transmit power
is always set to 0, causing associations to time out and similar
problems since we're transmitting with very little power. Correct
this by correcting the default user_power_level to -1.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Bisected-by: NNiel Lambrechts <niel.lambrechts@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

- ieee80211_wep_init(), which is called with rtnl_lock held, blocks in
   request_module() [waiting for modprobe to load a crypto module].

 - modprobe blocks in a call to flush_workqueue(), when it closes a TTY
   [presumably when it exits].

 - The workqueue item linkwatch_event() blocks on rtnl_lock.

There's no reason for wep_init() to be called with rtnl_lock held, so
just move it outside the critical section.
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

After experimenting with kexec with the last merges after 2.6.29, I've
had some problems when probing e100.  It would not read the eeprom.  After
some bisects, I realized this has been like that since forever (at least
2.6.18).  The problem is that shutdown is doing the same thing that
suspend does and puts the device in D3 state.  I couldn't find a way to
get the device back to a sane state in the probe function.  So, based on
some similar patches from Rafael J. Wysocki for e1000, e1000e, and ixgbe,
I wrote this one for e100.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The x_tables are organized with a table structure and a per-cpu copies
of the counters and rules. On older kernels there was a reader/writer 
lock per table which was a performance bottleneck. In 2.6.30-rc, this
was converted to use RCU and the counters/rules which solved the performance
problems for do_table but made replacing rules much slower because of
the necessary RCU grace period.

This version uses a per-cpu set of spinlocks and counters to allow to
table processing to proceed without the cache thrashing of a global
reader lock and keeps the same performance for table updates.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

char bname[5] is too small for the string "X GHz" when the null
terminator is taken into account.  Thus, turning on rate debugging
can crash unless we have lucky stack alignment.

Cc: stable@kernel.org
Reported-by: NParide Legovini <legovini@spiro.fisica.unipd.it>
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Under certain circumstances iwlwifi can get stuck and will no
longer accept scan requests, because the core code (cfg80211)
thinks that it's still processing one. This fixes one of the
points where it can happen, but I've still seen it (although
only with my radio-off-when-idle patch).
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rndis_wext_link_change() might be called from rndis_command() at
initialization stage and priv->workqueue/priv->work have not been
initialized yet. This causes invalid opcode at rndis_wext_bind on
some brands of bcm4320.

Fix by initializing workqueue/workers in rndis_wext_bind() before
rndis_command is used.

This bug has existed since 2.6.25, reported at:
	http://bugzilla.kernel.org/show_bug.cgi?id=12794Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl3945-base.c:1415: error: __ksymtab_iwl3945_rx_queue_reset causes a section type conflict

I am pretty sure that this is a compiler bug, so not to worry.  However,
as far as I can see, iwl-3945.o (the only user) and iwl3945-base.o are
always linked into the same module, so the EXPORT_SYMBOL (which causes
the problem) should not be needed.  Correct?
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The Bluetooth 2.1 specification introduced four different security modes
that can be mapped using Legacy Pairing and Simple Pairing. With the
usage of Simple Pairing it is required that all connections (except
the ones for SDP) are encrypted. So even the low security requirement
mandates an encrypted connection when using Simple Pairing. When using
Legacy Pairing (for Bluetooth 2.0 devices and older) this is not required
since it causes interoperability issues.

To support this properly the low security requirement translates into
different host controller transactions depending if Simple Pairing is
supported or not. However in case of Simple Pairing the command to
switch on encryption after a successful authentication is not triggered
for the low security mode. This patch fixes this and actually makes
the logic to differentiate between Simple Pairing and Legacy Pairing
a lot simpler.

Based on a report by Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth stack uses a reference counting for all established ACL
links and if no user (L2CAP connection) is present, the link will be
terminated to save power. The problem part is the dedicated pairing
when using Legacy Pairing (Bluetooth 2.0 and before). At that point
no user is present and pairing attempts will be disconnected within
10 seconds or less. In previous kernel version this was not a problem
since the disconnect timeout wasn't triggered on incoming connections
for the first time. However this caused issues with broken host stacks
that kept the connections around after dedicated pairing. When the
support for Simple Pairing got added, the link establishment procedure
needed to be changed and now causes issues when using Legacy Pairing

When using Simple Pairing it is possible to do a proper reference
counting of ACL link users. With Legacy Pairing this is not possible
since the specification is unclear in some areas and too many broken
Bluetooth devices have already been deployed. So instead of trying to
deal with all the broken devices, a special pairing timeout will be
introduced that increases the timeout to 60 seconds when pairing is
triggered.

If a broken devices now puts the stack into an unforeseen state, the
worst that happens is the disconnect timeout triggers after 120 seconds
instead of 4 seconds. This allows successful pairings with legacy and
broken devices now.

Based on a report by Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Use a different work_struct variables for add_conn() and del_conn() and
use single work queue instead of two for adding and deleting connections.

It eliminates the following error on a preemptible kernel:

[  204.358032] Unable to handle kernel NULL pointer dereference at virtual address 0000000c
[  204.370697] pgd = c0004000
[  204.373443] [0000000c] *pgd=00000000
[  204.378601] Internal error: Oops: 17 [#1] PREEMPT
[  204.383361] Modules linked in: vfat fat rfcomm sco l2cap sd_mod scsi_mod iphb pvr2d drm omaplfb ps
[  204.438537] CPU: 0    Not tainted  (2.6.28-maemo2 #1)
[  204.443664] PC is at klist_put+0x2c/0xb4
[  204.447601] LR is at klist_put+0x18/0xb4
[  204.451568] pc : [<c0270f08>]    lr : [<c0270ef4>]    psr: a0000113
[  204.451568] sp : cf1b3f10  ip : cf1b3f10  fp : cf1b3f2c
[  204.463104] r10: 00000000  r9 : 00000000  r8 : bf08029c
[  204.468353] r7 : c7869200  r6 : cfbe2690  r5 : c78692c8  r4 : 00000001
[  204.474945] r3 : 00000001  r2 : cf1b2000  r1 : 00000001  r0 : 00000000
[  204.481506] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment kernel
[  204.488861] Control: 10c5387d  Table: 887fc018  DAC: 00000017
[  204.494628] Process btdelconn (pid: 515, stack limit = 0xcf1b22e0)
Signed-off-by: NRoger Quadros <ext-roger.quadros@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In 2.6.25 we added UDP mem accounting.

This unfortunatly added a penalty when a frame is transmitted, since
we have at TX completion time to call sock_wfree() to perform necessary
memory accounting. This calls sock_def_write_space() and utimately
scheduler if any thread is waiting on the socket.
Thread(s) waiting for an incoming frame was scheduled, then had to sleep
again as event was meaningless.

(All threads waiting on a socket are using same sk_sleep anchor)

This adds lot of extra wakeups and increases latencies, as noted
by Christoph Lameter, and slows down softirq handler.

Reference : http://marc.info/?l=linux-netdev&m=124060437012283&w=2 

Fortunatly, Davide Libenzi recently added concept of keyed wakeups
into kernel, and particularly for sockets (see commit
37e5540b 
epoll keyed wakeups: make sockets use keyed wakeups)

Davide goal was to optimize epoll, but this new wakeup infrastructure
can help non epoll users as well, if they care to setup an appropriate
handler.

This patch introduces new DEFINE_WAIT_FUNC() helper and uses it
in wait_for_packet(), so that only relevant event can wakeup a thread
blocked in this function.

Trace of function calls from bnx2 TX completion bnx2_poll_work() is :
__kfree_skb()
 skb_release_head_state()
  sock_wfree()
   sock_def_write_space()
    __wake_up_sync_key()
     __wake_up_common()
      receiver_wake_function() : Stops here since thread is waiting for an INPUT
Reported-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMike Rapoport <mike@compulab.co.il>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>