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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Joe Perches <joe@perches.com>
Signed-off-by: David 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 3110bef78c
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: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel Halperin <dhalperi@cs.washington.edu>
Signed-off-by: Reinette 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette 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: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Includes minor improvements in debugging messages in iwl-4965.c,
function iwl4965_is_temp_calib_needed().
Signed-off-by: Frans 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: Reinette 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: Shanyu Zhao <shanyu.zhao@intel.com>
Signed-off-by: Henry Zhang <hongx.c.zhang@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette 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: Reinette 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.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: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cut down on redundant code, reorganize structure, and add/improve comments.
Should contain no functional changes.
Signed-off-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Tested-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John 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: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Short guard interval support is a local per-station parameter not a global
per-NIC parameter. (mac80211 will correctly remove SGI support from station
capabilities if the BSS does not permit it). This patch removes the short GI
support bitfield from the global iwl_ht_info struct and properly uses
per-station HT capabilities during rate selection.
Signed-off-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Driver's first notification of a new station from mac80211 can be through rate
selection API. This patch fixes a bug where, in this code path, the HT
capabilities of the new station were ignored.
Signed-off-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
With EDCA and HCCA we have 16 potential tid values. This is accommodated by
mac80211, but iwlwifi only supports EDCA. With this implementation it is
thus possible for mac80211 to request a tid that will cause iwlwifi to read
outside array bounds. A similar problem exists if traffic is received in an
unsupported category.
We add error checking to catch these situations.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some of the thermal throttle data structures and code
are really very intermingled with the sleep (power)
control code. They really do belong together in a way
since the thermal throttle code uses powersaving to
achieve its goal, but it's making it hard to work on
the powersave code. Split this up to make that easier.
I've also changed the antenna defines to an enum and
used the same enum for RX and TX.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Rename "fat" to "ht40"
The term "fat channel" is deprecated in favor of "HT40"
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Part 2 of Thermal Throttling Management -
Thermal Throttling feature is used to put NIC into low power state when
driver detect the Radio temperature reach pre-defined threshold
Two Thermal Throttling Management Methods; this patch introduce the
Advance Thermal Throttling:
TI-0: system power index, no tx/rx restriction, HT enabled
TI-1: power index 5, 1 spatial stream Tx, multiple spatial stream Rx, HT
enabled
TI-2: power index 5: 1 spatial stream Tx, 1 spatial stream Rx, HT
disabled
TI-CT-KILL: power index 5, no Tx, no Rx, HT disabled
For advance Thermal Throttling, CT_KILL_ENTER threshold and CT_KILL_EXIT
threshold are different; uCode will not stay awake until reach
CT_KILL_EXIT threshold.
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When performing rate scaling, if detected that the new rate
index is invalid, clear the search_better_tbl flag
so it will not be stuck in the loop.
Since the search table is already set up in uCode,
we need to empty out the the search table;
revert back to the "active" rate and throughput info.
Also pass the "active" table setup to uCode to make
sure the rate scale is functioning correctly.
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
All current rate control algorithms agree to send management and no-ack
frames at the lowest rate. They also agree to do this when sta
and the private rate control data is NULL. We add a hlper to mac80211
for this and simplify the rate control algorithm code.
Developers wishing to make enhancements to rate control algorithms
are for broadcast/multicast can opt to not use this in their
gate_rate() mac80211 callback.
Cc: Zhu Yi <yi.zhu@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: ipw3945-devel@lists.sourceforge.net
Cc: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Cc: Derek Smithies <derek@indranet.co.nz>
Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This removes the work around implemented for transmitting on
an unsupported band on iwlwifi. This was added via the patch:
8e1856e82cb8f541e925738bebfbc473420cda68:
iwlwifi: fix rs_get_rate WARN_ON()
Cc: Mohamed Abbas <mohamed.abbas@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Wey-Yi Guy