All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

82ca9341 added scary looking
but harmless error messages.  Make them clearer and make the
actual failure message show up with the same severity as the
harmless one.
Signed-off-by: NAndy Lutomirski <luto@mit.edu>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If RTS/CTS protection is needed for HT, wait until get operational
notification from mac80211, then inform uCode to switch to RTS/CTS
through RXON command.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

There's no sense in letting anything but internal
mac80211 functions set the initiator to anything
but WLAN_BACK_INITIATOR, since WLAN_BACK_RECIPIENT
is only valid when we have received a frame from
the peer, which we react to directly in mac80211.

The debugfs code I recently added got this wrong
as well.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch removes from drivers/net/ all the unnecessary
return; statements that precede the last closing brace of
void functions.

It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.

It also does not remove null void functions with return.

Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
  xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'

with some cleanups by hand.

Compile tested x86 allmodconfig only.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We currently have this check as a BUG_ON, which is being hit by people.
Previously it was an error with a recalculation if not current, return that
code.

The BUG_ON was introduced by:
commit 3110bef7
Author: Guy Cohen <guy.cohen@intel.com>
Date:   Tue Sep 9 10:54:54 2008 +0800

    iwlwifi: Added support for 3 antennas

... the portion adding the BUG_ON is reverted since we are encountering the error
and BUG_ON was created with assumption that error is not encountered.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The TX status code is currently abusing the ampdu_ack_map field (a bitmap) to
count the number of successfully received frames.  The comments in mac80211.h
show there are actually three different, relevant variables, of which we are
currently using two, both incorrectly. Fix this by making

- ampdu_ack_len -> the number of ACKed frames (i.e. successes)
- ampdu_ack_map -> the bitmap
- ampdu_len -> the total number of frames sent (i.e., attempts)

to match the header file (and verified with ath9k's usage) and updating Intel's
RS code to match.
Signed-off-by: NDaniel Halperin <dhalperi@cs.washington.edu>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Perform sanity check for turn on aggregation tid. Also remove the
option for turn on all the aggregation tids at once since it is
deprecated function and not being used.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Even the initial single/dual stream values will be overridden later when
issue link quality command; but still make sense not to use hard-code
value during initialization. Single/Dual stream mask are used to indicate the
best antenna for SISO/MIMO; different NIC has different tx antenna
configuration; so the parameter need to based on the valid tx antenna.

1x2 device: single tx antenna available, only SISO is valid
configuration, but still need to set up MIMO configuration, so set it up
with antenna A & B as default.
2x2 device: two tx antenna available, dual_stream will use both valid
antenna.

3x3 device: three tx antenna available, skip the first antenna and
choice the second and third antenna for dual_stream.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Fixes:
CC [M]  drivers/net/wireless/iwlwifi/iwl-agn-rs.o
drivers/net/wireless/iwlwifi/iwl-agn-rs.c: In function ‘rs_get_rate’:
drivers/net/wireless/iwlwifi/iwl-agn-rs.c:2419: warning: unused variable ‘priv’
CC [M]  drivers/net/wireless/iwlwifi/iwl-sta.o
drivers/net/wireless/iwlwifi/iwl-sta.c: In function ‘iwl_send_add_sta’:
drivers/net/wireless/iwlwifi/iwl-sta.c:197: warning: unused variable ‘sta_id’

drivers/net/wireless/iwlwifi/iwl-3945.c: In function ‘iwl3945_rx_reply_rx’:
drivers/net/wireless/iwlwifi/iwl-3945.c:601: warning: unused variable ‘rx_stats_noise_diff’
drivers/net/wireless/iwlwifi/iwl-3945.c:600: warning: unused variable ‘rx_stats_sig_avg’
drivers/net/wireless/iwlwifi/iwl-3945-rs.c: In function ‘rs_get_rate’:
drivers/net/wireless/iwlwifi/iwl-3945-rs.c:650: warning: unused variable ‘priv’
Reported-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Includes minor improvements in debugging messages in iwl-4965.c,
function iwl4965_is_temp_calib_needed().
Signed-off-by: NFrans Pop <elendil@planet.nl>
Cc: Zhu Yi <yi.zhu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Intel Linux Wireless <ilw@linux.intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

When collecting tx data for non-aggregation packets in rate scaling, if
the tx data matches "other table", it still uses current table to update
the stats and calculate average throughput in function rs_collect_tx_data().
This can mess up the rate scaling data structure and cause a kernel panic
in a BUG_ON statement in rs_rate_scale_perform().

To fix this bug, we pass table pointer instead of window pointer (pointed
to by table pointer) to function rs_collect_tx_data() so that the table
being used is consistent.
Signed-off-by: NShanyu Zhao <shanyu.zhao@intel.com>
Signed-off-by: NHenry Zhang <hongx.c.zhang@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

We go to great lengths to calculate this value
that is never used by mac80211. Additionally,
it is now deprecated by mac80211 and is causing
driver compilation to give warnings.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

The only caller of this is iwl_rs_rate_init
which is only called with a valid sta_id.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

mac80211 recently implemented two new callbacks that are used to request
station add/remove from the driver. The benefot from these new callbacks
are that they enable the driver to sleep while performing this work.

This is a big patch since a few things need to be coordinated in this move.
First we need to decouple station management from rate scaling, which
caused a lot of code to be moved and/or deleted. Next we needed to tie in
with mac80211's station management callback and let it direct our station
management as well as trigger the rate scaling initialization.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

This variable is assigned a default value,
but then assigned zero as soon as mac80211
calls a change channel (which will happen
right after the hw is started) and after
that it never changes again.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Updating the variables last_rx_rssi, last_tsf
and last_beacon_time needs a lot of code but
they are not actually used in iwlagn (only in
3945) so we can move them to the 3945 specific
data.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Error checking for aggregation frames should go into aggregation queue,
if aggregation queue not available, use legacy queue instead.
Also make sure the aggregation queue is available to activate,
if driver and mac80211 is out-of-sync, try to disable the queue and
sync-up with mac80211.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NZhu Yi <yi.zhu@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Set the correct Read/Write file permission for iwlwifi debugfs files
based on the functionality of the files
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The entire aggregation code currently operates on the
hw pointer and station addresses, but that needs to
change to make stations purely per-vif; As one step
preparing for that make the aggregation code callable
with the station, or by the combination of virtual
interface and station address.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When 802.11g was introduced, we had RTS/CTS and CTS-to-Self protection
mechanisms. In an HT Beacon, HT stations use the "Operating Mode" field
in the HT Information Element to determine whether or not to use
protection.

The Operating Mode field has 4 possible settings: 0-3:
Mode 0: If all stations in the BSS are 20/40 MHz HT capable, or if the
BSS is 20/40 MHz capable, or if all stations in the BSS are 20 MHz HT
stations in a 20 MHz BSS
Mode 1: used if there are non-HT stations or APs using the primary or
secondary channels
Mode 2: if only HT stations are associated in the BSS and at least one
20 MHz HT station is associated.
Mode 3: used if one or more non-HT stations are associated in the BSS.

When in operating modes 1 or 3, and the Use_Protection field is 1 in the
Beacon's ERP IE, all HT transmissions must be protected using RTS/CTS or
CTS-to-Self.

By default, CTS-to-self is the preferred protection mechanism for less
overhead and higher throughput; but using the full RTS/CTS will better
protect the inner exchange from interference, especially in
highly-congested environment.

For 6000 series WIFI NIC, RTS/CTS protection mechanism is the
recommended choice for HT traffic based on the HW design.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This fits better in how the callbacks operate (alloc does allocation and
init does initialization). This also helps if we later want to do our own
initialization without relying on the mac80211 allocation.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently mac80211 initializes the rate scaling before notifying the driver
of the station's existence. The driver dealt with this by not relying on
mac80211's station notifications and instead mixing this functionality with
the rate scaling code and other places. To clean this up the driver needs
to do rate scaling initialization after being notified of the station, this
can be done if the rate scaling information forms part of the station
information passed from mac80211 to driver.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Move to header file so they can be included and used in other parts of the
driver.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Multiple MPDUs can be aggregated, transmitted, and finally acknowledged
together using a single BA frame. Block ACK (BA) contains
bitmap size of 64*16 bits so the maximum frame count is 64.
The default value of aggregation frame count suggested by uCode is 31 to
achieve best performance.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Current rate scale algorithm fluctuates between different MIMO modes fairly
rapidly, causing widely varying performance. These fluctuations occur because in
the rate_scale tables for expected throughput the values are not very different
for different modes.

However, when aggregation is turned on and MAC overhead is reduced, the
expected throughput for different MIMO modes grows and different modes have
vastly different performance. Add expected throughput tables for this case.

We also need to keep track of aggregation status per-station, so we add the
"is_agg" field to struct lq_sta.

Also includes cleanup of comments and variable names in/around the affected
code.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Cut down on redundant code, reorganize structure, and add/improve comments.
Should contain no functional changes.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When 802.11g was introduced, we had RTS/CTS and CTS-to-Self protection
mechanisms. In an HT Beacon, HT stations use the "Operating Mode" field
in the HT Information Element to determine whether or not to use
protection.

The Operating Mode field has 4 possible settings: 0-3:
Mode 0: If all stations in the BSS are 20/40 MHz HT capable, or if the
BSS is 20/40 MHz capable, or if all stations in the BSS are 20 MHz HT
stations in a 20 MHz BSS
Mode 1: used if there are non-HT stations or APs using the primary or
secondary channels
Mode 2: if only HT stations are associated in the BSS and at least one
20 MHz HT station is associated.
Mode 3: used if one or more non-HT stations are associated in the BSS.

When in operating modes 1 or 3, and the Use_Protection field is 1 in the
Beacon's ERP IE, all HT transmissions must be protected using RTS/CTS or
CTS-to-Self.

By default, CTS-to-self is the preferred protection mechanism for less
overhead and higher throughput; but using the full RTS/CTS will better
protect the inner exchange from interference, especially in
highly-congested environment.

For 6000 series WIFI NIC, RTS/CTS protection mechanism is the
recommended choice for HT traffic based on the HW design.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Daniel Halperin pointed out that the naming
here is rather inconsistent with at least 3
different names being used for one thing in
different contexts. Rename the struct to
iwl_ht_config (rather than iwl_ht_info) and
use ht_conf as a variable for it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We can not assume antenna "A" is the first valid anttena for
all the NIC. Need to make sure choice the correct antenna based on
h/w configuration for transmit to avoid sending frame on invalid
antenna
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we cleaned up the driver to properly tell mac80211 about HT rates
("iwlwifi: use iwl_hwrate_get_mac80211_idx where appropriate"), we broke
internal rate indexing in 2.4 GHz band.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Tested-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We can not assume antenna "A" is the first valid anttena for
all the NIC. Need to make sure choice the correct antenna based on
h/w configuration for transmit to avoid sending frame on invalid
antenna
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we cleaned up the driver to properly tell mac80211 about HT rates
("iwlwifi: use iwl_hwrate_get_mac80211_idx where appropriate"), we broke
internal rate indexing in 2.4 GHz band.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Tested-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

For HT packets, mac80211 expects the rate_idx to be an MCS number, which is the
lower byte of rate_n_flags.  However, iwl_hwrate_to_plcp_idx takes the MCS
number and reduces it down to the range 0-8 (6 to 60 Mbps), removing the bits
that signify multiply streams, HT40 Duplicate mode, or unequal modulation.
This version is used for various internal purposes through the driver.

Add the function iwl_hwrate_get_mac80211_idx, an alternate version which takes
the rate and the band and returns the mac80211 index (MCS, for HT packets, and
PLCP rate, for legacy packets).
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_supported_band is supposed to only contain legacy rates in the
bitrates table (HT rates go in the ieee80211_sta_ht_cap substruct).  Make
iwlwifi driver obey this restriction by removing the 60 Mbps rate. Also, clean
up a few pieces of other code that formerly relied on 60 Mbps being in
sband->bitrates.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Clear the flags (most importantly, the IEEE80211_TX_RC_MCS flag)
when sending a non-HT packet so that the rate index can be properly treated.
This fixes the reporting of legacy rates in wireless-extensions for packets
sent after an HT packet.
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Green-field mode should be configured in the HT station table.  This patch uses
both the per-station GF support flag as well as the current BSS HT operation
mode (non-GF stations present flag).

Added the "ht_greenfield_support" field to struct iwl_cfg to replace the
device-specific check in rs_use_green().  That check has been moved to
iwlcore_init_ht_hw_capab().
Signed-off-by: NDaniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>