To simplify the locking and not require cfg80211_mutex
(which nl80211 uses to access the global regdomain) and
also to make it possible for drivers to access their
wiphy->regd safely, use RCU to protect these pointers.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of assigning after calling the function do
it inside the function. This will later avoid a
period of time where the pointer is NULL.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The channel bandwidth handling isn't really quite right,
it assumes that a 40 MHz channel is really two 20 MHz
channels, which isn't strictly true. This is the way the
regulatory database handling is defined right now though
so remove the logic to handle other channel widths.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's a bug with the world regulatory domain, it
can be updated any time which is different from all
other regdomains that can only be updated once after
a request for them. Fix this by adding a check for
"processed" to the reg_is_valid_request() function
and clear that when doing a request.

While looking at this I also found another locking
bug, last_request is protected by the reg_mutex not
the cfg80211_mutex so the code in nl80211 is racy.
Remove that code as it only tries to prevent an
allocation in an error case, which isn't necessary.
Then the function can also become static and locking
in nl80211 can have a smaller scope.

Also change __set_regdom() to do the checks earlier
and not different for world/other regdomains.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

wiphy_apply_custom_regulatory() doesn't have to hold
the regulatory mutex as it only modifies the given
wiphy with the given regulatory domain, it doesn't
access any global regulatory data.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Many places that currently check that cfg80211_mutex
is held don't actually use any data protected by it.
The functions that need to hold the cfg80211_mutex
are the ones using the cfg80211_regdomain variable,
so add the lock assertion to those and clarify this
in the comments.

The reason for this is that nl80211 uses the regdom
without being able to hold reg_mutex.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function itself has dual-purpose: it can
retrieve from a given regdomain or from the
globally installed one. Change it to have a
single purpose only: to look up from a given
regdomain. Pass the correct regdomain in the
freq_reg_info() function instead.

This also changes the locking rules for it,
no locking is required any more.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Even if it never happens and is hidden behind the
debug config option, it's completely useless: the
calltrace will only show module loading.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

toupper() only modifies lower-case letters, so
the isalpha() check is redundant; remove it.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Use list_splice_tail_init() and also simplify the locking.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This code is a bit too BUG_ON happy, remove all
instances and while doing so make some code a bit
smarter by passing the right pointer instead of
indices into arrays.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is pretty much useless since get_wiphy_idx()
always returns true since it's always called with
a valid wiphy pointer.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of treating special error codes specially,
like -EALREADY, introduce a real enum for all the
needed possibilities and use it.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It would be a major problem if anything were to run
concurrently while the module is being unloaded so
remove the locking that doesn't help anything.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Clean up various things like indentation, extra
parentheses, too many/few line breaks, etc.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to unlock before calling
queue_regulatory_request(), so simplify
the function.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to test whether a list is
empty or not before iterating.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Use ERR_PTR/IS_ERR to return the result or errors,
also do some code cleanups.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

As the dummy_rule (also renamed from irule) is only
used for output by the reg_rules_intersect() function
there's no need to clear it at all, remove that.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to allocate one reg rule more
than will be used, reduce the allocations. The
allocation in nl80211 already doesn't allocate
too much space.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When intersecting rules, we count first to know how many
rules need to be allocated, and then do the intersection
into the allocated array. However, the code doing this
writes past the end of the array because it attempts to
do all intersections. Make it stop when the right number
of rules has been reached.
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When a BSS struct is updated, the IEs are currently
overwritten or freed. This can lead to races if some
other CPU is accessing the BSS struct and using the
IEs concurrently.

Fix this by always allocating the IEs in a new struct
that holds the data and length and protecting access
to this new struct with RCU.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When in world roaming mode, allow 40 MHz to be used
on channels 12 and 13 so that an AP that is, e.g.,
using HT40+ on channel 9 (in the UK) can be used.

Cc: stable@vger.kernel.org
Reported-by: NEddie Chapman <eddie@ehuk.net>
Tested-by: NEddie Chapman <eddie@ehuk.net>
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A few places touch chan->max_power based on updated tx power rules, but
forget to do the same to chan->max_reg_power.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The current regulatory code on cfg80211 performs a check to
see if a regulatory rule belongs to an IEEE band so that if
a Country IE is received and no rules are specified for a
band (which is allowed by IEEE) those bands are left intact.
The current band check assumes a rule is bound to a band
if the rule's start or end frequency is less than 2 GHz
apart from the center of frequency being inspected.

In order to support 60 GHz for 802.11ad we need to increase
this to account for the channel spacing of 2160 MHz whereby
a channel somewhere in the middle of a regulatory rule may
be more than 2 GHz apart from either the beginning or
end of the frequency rule.

Without a fix for this even though channels 1-3 are allowed world
wide on the rule (57240 - 63720 @ 2160), channel 2 at 60480 MHz
will end up getting disabled given that it is 3240 MHz from
both the frequency rule start and end frequency. Fix this by
using 2 GHz separation assumption for the 2.4 and 5 GHz bands
but for 60 GHz use a 10 GHz separation before assuming a rule
is not part of the band.

Since we have no 802.11ad drivers yet merged this change has
no impact to existing Linux upstream device drivers.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Acked-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When call_crda() is called we kick off a witch hunt search
for the same regulatory domain on our internal regulatory
database and that work gets kicked off on a workqueue, this
is done while the cfg80211_mutex is held. If that workqueue
kicks off it will first lock reg_regdb_search_mutex and
later cfg80211_mutex but to ensure two CPUs will not contend
against cfg80211_mutex the right thing to do is to have the
reg_regdb_search() wait until the cfg80211_mutex is let go.

The lockdep report is pasted below.

cfg80211: Calling CRDA to update world regulatory domain

======================================================
[ INFO: possible circular locking dependency detected ]
3.3.8 #3 Tainted: G           O
-------------------------------------------------------
kworker/0:1/235 is trying to acquire lock:
 (cfg80211_mutex){+.+...}, at: [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

but task is already holding lock:
 (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (reg_regdb_search_mutex){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<81645778>] is_world_regdom+0x9f8/0xc74 [cfg80211]

-> #1 (reg_mutex#2){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<8164539c>] is_world_regdom+0x61c/0xc74 [cfg80211]

-> #0 (cfg80211_mutex){+.+...}:
       [<800a77b8>] __lock_acquire+0x10d4/0x17bc
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex#2 --> reg_regdb_search_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(reg_regdb_search_mutex);
                               lock(reg_mutex#2);
                               lock(reg_regdb_search_mutex);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

3 locks held by kworker/0:1/235:
 #0:  (events){.+.+..}, at: [<80089a00>] process_one_work+0x230/0x460
 #1:  (reg_regdb_work){+.+...}, at: [<80089a00>] process_one_work+0x230/0x460
 #2:  (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

stack backtrace:
Call Trace:
[<80290fd4>] dump_stack+0x8/0x34
[<80291bc4>] print_circular_bug+0x2ac/0x2d8
[<800a77b8>] __lock_acquire+0x10d4/0x17bc
[<800a8384>] lock_acquire+0x60/0x88
[<802950a8>] mutex_lock_nested+0x54/0x31c
[<816468a4>] set_regdom+0x78c/0x808 [cfg80211]
Reported-by: NFelix Fietkau <nbd@openwrt.org>
Tested-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Signed-off-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The only case where intersected_rd can become non NULL is within an if. All
paths from that if return, so the end chunk has therefore squawked its
last and is no more.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Using list_move_tail() instead of list_del() + list_add_tail().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Restore the default state to the "beacon_found" flag when
the channel flags are restored.  Otherwise, we can end up
with a channel that we can no longer transmit on even when
we can see beacons on that channel.
Signed-off-by: NPaul Stewart <pstew@chromium.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently the only way for wireless drivers to tell whether or not OFDM
is allowed on the current channel is to check the regulatory
information. However, this requires hodling cfg80211_mutex, which is not
visible to the drivers.

Other regulatory restrictions are provided as flags in the channel
definition, so let's do similarly with OFDM. This patch adds a new flag,
IEEE80211_CHAN_NO_OFDM, to tell drivers that OFDM on a channel is not
allowed. This flag is set on any channels for which regulatory indicates
that OFDM is prohibited.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Tested-by: NArend van Spriel <arend@broadcom.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

commit eccc068e
Author: Hong Wu <Hong.Wu@dspg.com>
Date:   Wed Jan 11 20:33:39 2012 +0200

    wireless: Save original maximum regulatory transmission power for the calucation of the local maximum transmit pow

changed the way we calculate chan->max_power as min(chan->max_power,
chan->max_reg_power). That broke rt2x00 (and perhaps some other
drivers) that do not set chan->max_power. It is not so easy to fix this
problem correctly in rt2x00.

According to commit eccc068e changelog, change claim only to save
maximum regulatory power - changing setting of chan->max_power was side
effect. This patch restore previous calculations of chan->max_power and
do not touch chan->max_reg_power.

Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

should fix the following issue

	[ 3229.815012] [ BUG: lock held when returning to user space! ]
	[ 3229.815016] 3.5.0-rc7-wl #28 Tainted: G        W  O
	[ 3229.815017]
	------------------------------------------------
	[ 3229.815019] wpa_supplicant/5783 is leaving the kernel with locks still held!
	[ 3229.815022] 1 lock held by wpa_supplicant/5783:
	[ 3229.815023]  #0: (reg_mutex){+.+.+.}, at: [<fa65834d>]
	reg_last_request_cell_base+0x1d/0x60 [cfg80211]

Cc: Luis Rodriguez <mcgrof@gmail.com>
Signed-off-by: NMohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Tested-by: NLuciano Coelho <coelho@ti.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

regulatory_update() just calls wiphy_update_regulatory().
wiphy_update_regulatory() assumes you already have
the reg_mutex held so just move the call within locking
context and kill the superfluous regulatory_update().
Signed-off-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Now that we have wiphy_regulatory_register() we can
tuck away the core's regulatory_update() call there
and make it static.
Signed-off-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This makes it clearer what we're doing. This now makes a bit
more sense given that regardless of the wiphy if the cell
base station hint feature is supported we will be modifying the
way the regulatory core behaves.
Signed-off-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Cellular base stations can provide hints to cfg80211 about
where they think we are. This can be done for example on
a cell phone. To enable these hints we simply allow them
through as user regulatory hints but we allow userspace
to clasify the hint as either coming directly from the
user or coming from a cellular base station. This option
is only available when you enable
CONFIG_CFG80211_CERTIFICATION_ONUS.

The base station hints themselves will not be processed
by the core unless at least one device on the system
supports this feature.
Signed-off-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

While adding regulatory support to ath6kl I noticed that I easily
got the regulatory code confused. The way to reproduce the bug was:

1. iw reg set FI (in userspace)
2. cfg80211 calls ath6kl_reg_notify(FI)
3. ath6kl sets regdomain in firmware
4. firmware sends regdomain event to notify about the new regdomain (FI)
5. ath6kl calls regulatory_hint(FI)

And this (from FI to FI transition) confuses cfg80211 and after that I
only get "Pending regulatory request, waiting for it to be
processed...." messages and regdomain changes won't work anymore.

The reason why ath6kl calls regulatory_hint() is that firmware can change
the regulatory domain by it's own, for example due to 11d IEs. I could
of course workaround this in ath6kl but I think it's better to handle
the case in cfg80211.

The fix is pretty simple, use a different error code if the regdomain is
same and then just set the request processed so that it doesn't block new
requests.
Signed-off-by: NKalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add regulatory rule for the 60g band
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

reg_timeout_work() calls restore_regulatory_settings() which
takes cfg80211_mutex.

reg_set_request_processed() already holds cfg80211_mutex
before calling cancel_delayed_work_sync(reg_timeout),
so it might deadlock.

Call the async cancel_delayed_work instead, in order
to avoid the potential deadlock.

This is the relevant lockdep warning:

cfg80211: Calling CRDA for country: XX

======================================================
[ INFO: possible circular locking dependency detected ]
3.4.0-rc5-wl+ #26 Not tainted
-------------------------------------------------------
kworker/0:2/1391 is trying to acquire lock:
 (cfg80211_mutex){+.+.+.}, at: [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211]

but task is already holding lock:
 ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 ((reg_timeout).work){+.+...}:
       [<c008fd44>] validate_chain+0xb94/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c005b600>] wait_on_work+0x4c/0x154
       [<c005c000>] __cancel_work_timer+0xd4/0x11c
       [<c005c064>] cancel_delayed_work_sync+0x1c/0x20
       [<bf28b274>] reg_set_request_processed+0x50/0x78 [cfg80211]
       [<bf28bd84>] set_regdom+0x550/0x600 [cfg80211]
       [<bf294cd8>] nl80211_set_reg+0x218/0x258 [cfg80211]
       [<c03c7738>] genl_rcv_msg+0x1a8/0x1e8
       [<c03c6a00>] netlink_rcv_skb+0x5c/0xc0
       [<c03c7584>] genl_rcv+0x28/0x34
       [<c03c6720>] netlink_unicast+0x15c/0x228
       [<c03c6c7c>] netlink_sendmsg+0x218/0x298
       [<c03933c8>] sock_sendmsg+0xa4/0xc0
       [<c039406c>] __sys_sendmsg+0x1e4/0x268
       [<c0394228>] sys_sendmsg+0x4c/0x70
       [<c0013840>] ret_fast_syscall+0x0/0x3c

-> #1 (reg_mutex){+.+.+.}:
       [<c008fd44>] validate_chain+0xb94/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c04734dc>] mutex_lock_nested+0x48/0x320
       [<bf28b2cc>] reg_todo+0x30/0x538 [cfg80211]
       [<c0059f44>] process_one_work+0x2a0/0x480
       [<c005a4b4>] worker_thread+0x1bc/0x2bc
       [<c0061148>] kthread+0x98/0xa4
       [<c0014af4>] kernel_thread_exit+0x0/0x8

-> #0 (cfg80211_mutex){+.+.+.}:
       [<c008ed58>] print_circular_bug+0x68/0x2cc
       [<c008fb28>] validate_chain+0x978/0x10f0
       [<c0090b68>] __lock_acquire+0x8c8/0x9b0
       [<c0090d40>] lock_acquire+0xf0/0x114
       [<c04734dc>] mutex_lock_nested+0x48/0x320
       [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211]
       [<bf28b200>] reg_timeout_work+0x1c/0x20 [cfg80211]
       [<c0059f44>] process_one_work+0x2a0/0x480
       [<c005a4b4>] worker_thread+0x1bc/0x2bc
       [<c0061148>] kthread+0x98/0xa4
       [<c0014af4>] kernel_thread_exit+0x0/0x8

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex --> (reg_timeout).work

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((reg_timeout).work);
                               lock(reg_mutex);
                               lock((reg_timeout).work);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

2 locks held by kworker/0:2/1391:
 #0:  (events){.+.+.+}, at: [<c0059e94>] process_one_work+0x1f0/0x480
 #1:  ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480

stack backtrace:
[<c001b928>] (unwind_backtrace+0x0/0x12c) from [<c0471d3c>] (dump_stack+0x20/0x24)
[<c0471d3c>] (dump_stack+0x20/0x24) from [<c008ef70>] (print_circular_bug+0x280/0x2cc)
[<c008ef70>] (print_circular_bug+0x280/0x2cc) from [<c008fb28>] (validate_chain+0x978/0x10f0)
[<c008fb28>] (validate_chain+0x978/0x10f0) from [<c0090b68>] (__lock_acquire+0x8c8/0x9b0)
[<c0090b68>] (__lock_acquire+0x8c8/0x9b0) from [<c0090d40>] (lock_acquire+0xf0/0x114)
[<c0090d40>] (lock_acquire+0xf0/0x114) from [<c04734dc>] (mutex_lock_nested+0x48/0x320)
[<c04734dc>] (mutex_lock_nested+0x48/0x320) from [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211])
[<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) from [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211])
[<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) from [<c0059f44>] (process_one_work+0x2a0/0x480)
[<c0059f44>] (process_one_work+0x2a0/0x480) from [<c005a4b4>] (worker_thread+0x1bc/0x2bc)
[<c005a4b4>] (worker_thread+0x1bc/0x2bc) from [<c0061148>] (kthread+0x98/0xa4)
[<c0061148>] (kthread+0x98/0xa4) from [<c0014af4>] (kernel_thread_exit+0x0/0x8)
cfg80211: Calling CRDA to update world regulatory domain
cfg80211: World regulatory domain updated:
cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:   (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)

Cc: stable@kernel.org
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It has happened twice now where elaborate troubleshooting has
undergone on systems where CONFIG_CFG80211_INTERNAL_REGDB [0]
has been set but yet net/wireless/db.txt was not updated.

Despite the documentation on this it seems system integrators could
use some more help with this, so throw out a kernel warning at boot time
when their database is empty.

This does mean that the error-prone system integrator won't likely
realize the issue until they boot the machine but -- it does not seem
to make sense to enable a build bug breaking random build testing.

[0] http://wireless.kernel.org/en/developers/Regulatory/CRDA#CONFIG_CFG80211_INTERNAL_REGDB

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Youngsin Lee <youngsin@qualcomm.com>
Cc: Raja Mani <rmani@qca.qualcomm.com>
Cc: Senthil Kumar Balasubramanian <senthilb@qca.qualcomm.com>
Cc: Vipin Mehta <vipimeht@qca.qualcomm.com>
Cc: yahuan@qca.qualcomm.com
Cc: jjan@qca.qualcomm.com
Cc: vthiagar@qca.qualcomm.com
Cc: henrykim@qualcomm.com
Cc: jouni@qca.qualcomm.com
Cc: athiruve@qca.qualcomm.com
Cc: cjkim@qualcomm.com
Cc: philipk@qca.qualcomm.com
Cc: sunnykim@qualcomm.com
Cc: sskwak@qualcomm.com
Cc: kkim@qualcomm.com
Cc: mattbyun@qualcomm.com
Cc: ryanlee@qualcomm.com
Cc: simbap@qualcomm.com
Cc: krislee@qualcomm.com
Cc: conner@qualcomm.com
Cc: hojinkim@qualcomm.com
Cc: honglee@qualcomm.com
Cc: johnwkim@qualcomm.com
Cc: jinyong@qca.qualcomm.com
Cc: stable@vger.kernel.org
Signed-off-by: NLuis R. Rodriguez <mcgrof@frijolero.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>