Commit Graph

74 Commits

Author SHA1 Message Date
Sujith 0ce024cbcd ath9k: Clarify Interrupt mitigation
ath9k currently supports only RX interrupt
mitigation.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-12-22 13:56:10 -05:00
Gabor Juhos a9a29ce674 ath9k: enable 2GHz band only if the device supports it
Currently, the 2GHz band is enabled unconditionally, even if the device
does not support it.

Changes-licensed-under: ISC
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-12-04 14:16:23 -05:00
Luis R. Rodriguez f4709fdf68 ath9k: Fix maximum tx fifo settings for single stream devices
Atheros single stream AR9285 and AR9271 have half the PCU TX FIFO
buffer size of that of dual stream devices. Dual stream devices
have a max PCU TX FIFO size of 8 KB while single stream devices
have 4 KB. Single stream devices have an issue though and require
hardware only to use half of the amount of its capable PCU TX FIFO
size, 2 KB and this requires a change in software.

Technically a change would not have been required (except for frame
burst considerations of 128 bytes) if these devices would have been
able to use the full 4 KB of the PCU TX FIFO size but our systems
engineers recommend 2 KB to be used only. We enforce this through
software by reducing the max frame triggger level to 2 KB.

Fixing the max frame trigger level should then have a few benefits:

  * The PER will now be adjusted as designed for underruns when the
    max trigger level is reached. This should help alleviate the
    bus as the rate control algorithm chooses a slower rate which
    should ensure frames are transmitted properly under high system
    bus load.

  * The poll we use on our TX queues should now trigger and work
    as designed for single stream devices. The hardware passes
    data from each TX queue on the PCU TX FIFO queue respecting each
    queue's priority. The new trigger level ensures this seeding of
    the PCU TX FIFO queue occurs as designed which could mean avoiding
    false resets and actually reseting hw correctly when a TX queue
    is indeed stuck.

  * Some undocumented / unsupported behaviour could have been triggered
    when the max trigger level level was being set to 4 KB on single
    stream devices. Its not clear what this issue was to me yet.

Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Cc: Bennyam Malavazi <bennyam.malavazi@atheros.com>
Cc: Stephen Chen <stephen.chen@atheros.com>
Cc: Shan Palanisamy <shan.palanisamy@atheros.com>
Cc: Paul Shaw <paul.shaw@atheros.com>
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-28 15:04:52 -05:00
Felix Fietkau 545750d36f ath9k: properly use the mac80211 rate control api
This patch changes ath9k to pass proper MCS indexes and flags
between the RC and the rest of the driver code.
sc->cur_rate_table remains, as it's used by the RC code internally,
but the rest of the driver code no longer uses it, so a potential
new RC for ath9k would not have to update it.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-28 15:04:24 -05:00
John W. Linville 04658fba23 ath9k: remove warnings related to signed/unsigned type mismatch
CC [M]  drivers/net/wireless/ath/ath9k/recv.o
drivers/net/wireless/ath/ath9k/recv.c: In function `ath_rx_prepare':
drivers/net/wireless/ath/ath9k/recv.c:208: warning: comparison is always true due to limited range of data type
drivers/net/wireless/ath/ath9k/recv.c:220: warning: comparison is always false due to limited range of data type

Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-25 15:20:50 -05:00
Sujith 201cd6cce4 ath9k: Remove a few unused functions
ATH9K_ANT_VARIABLE is the default diversity control used.
Consequently ath9k_hw_decrease_chain_power() does nothing.
ath9k_hw_setantennaswitch() is unused too.

Also, gbeacon_rate is unused.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-18 17:09:12 -05:00
Vasanthakumar Thiagarajan c90017dd43 ath9k_hw: Fix possible OOB array indexing in gen_timer_index[] on 64-bit
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-13 17:43:59 -05:00
Luis R. Rodriguez 30cbd42265 ath9k_hw: move ath_extend_tsf() to hw code to share as ath9k_hw_extend_tsf()
This will be shared between ath9k and ath9k_htc.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-11 17:09:04 -05:00
Luis R. Rodriguez ae478cf69e ath9k_hw: make spur mitigation a callback
This only differs between single-chip solutions and non single-chip
solutions.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:50:38 -04:00
Luis R. Rodriguez e68a060b5d ath9k_hw: use a callback for frequency change
This avoids a branch on every channel change.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:50:37 -04:00
Luis R. Rodriguez dc51dd5039 ath9k_hw: rename ath9k_hw_rf_free() to ath9k_hw_rf_free_ext_banks()
This clarifies this is only required for external radios.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:50:37 -04:00
Luis R. Rodriguez 131d1d036a ath9k_hw: start documenting 802.11n RF anlong front ends
Document what we can about the RF analog front ends (radios)
of Atheros 802.11n devices. What should be clearer now is the
what we do for old pre AR5416 and AR5418 MAC based devices in
comparison to the modern sigle-chip 802.11n solutions.

All devices after AR9280 are single chip and require less
programming -- the RF registers no longer need to be initialized
as they all have the RF analog front end embedded together with
the MAC/BB; this includes the AR9271. Older devices such as the
ones with the AR5416 MACs (PCI) or AR5418 MACs (PCI-E) have an
external 2.4 GHz AR2133 radio or a dual band 2.4 GHz / 5 GHz
AR5133 radio. These external radios require additional programming
of the RF registers.

Clarify which parts are for what devices and which code is
shared. This patch has no functional changes.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:50:37 -04:00
Luis R. Rodriguez 8564328d85 ath9k_hw: update register initialization/reset values for ar9271
This update the register initialization/reset values (aka initvals)
for ar9271 based on the last recommended values on 2009-06-04 by our
systems engineering team.

The changes account for:

  * Supporting ar9271 1.0 and ar9271 1.1 together, the difference
    is bb_spectral_scan_ena, for 1.0 we'll set this to 0x1.

  * Ensuring we get the correct noise floor values -115 ~ -118
    when we enable bb_enable_ant_div_lnadiv=0 and
    mc_tx_def_ant_sel=1. Previous to this we would get noise
    floor values in the range -50 ~ -80. To fix settings for
    the registers:

     - bb_ch1_xatten1_db
     - bb_ch1_xatten2_db
     - bb_ch1_xatten1_margin
     - bb_ch1_xatten2_margin
     - bb_ch1_gain_force
     - bb_ch1_xatten2_hyst_margin
     - bb_ch1_xatten1_hyst_margin
     - bb_ch1_max_oc_gain

  * 0x8120[2] mc_mic_new_location_enable is changed to 0x1. The MAC team
    suggest to set this value.

  * 0x9910[0] bb_spectral_scan_ena is changed to 0x0.
    For ar9271 1.1 we don't need to enable this bit.

Cc: Stephen Chen <Stephen.Chen@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:50:36 -04:00
Luis R. Rodriguez f934c4d9de ath9k_hw: distinguish single-chip solutions on initial probe print
Devices with external radios have revisions which we can count on.
On single chip solutions these EEPROM values for these radio revision
also exist but are not meaningful as the radios are embedded onto the
same chip. Each single-chip device evolves together as one device.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:49:18 -04:00
Luis R. Rodriguez 2da4f01a09 ath9k_hw: move mac name and rf name helpers to hw code
These are shared between ath9k and the future ath9k_htc driver.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-30 16:49:18 -04:00
Luis R. Rodriguez bc974f4a23 atheros: define a common priv struct
hw code should never use private driver data, but
sometimes we need a backpointer so just stuff it on
the common ath struct.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:42 -04:00
Luis R. Rodriguez 7976b4263c ath9k_hw: add AR9271 srev and device ID to allow hw to support ar9271
This allows for hw support to be enabled for ar9271.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:42 -04:00
Senthil Balasubramanian 63a75b912b ath9k: Reduce PLL Settle time and eliminate redundant PLL calls.
Reduce PLL Settle time and eliminate redundant PLL calls. Also reduce
the LoadNF timeout from 10 msec to 250usec as the 10 msec timeout was
hit with AR9285 in some cases.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:40 -04:00
Sujith 193cd4585e ath9k: Update INI release for AR9287
If the current channel is between 2412 and 2472 MHz and if the channel is
changing to 2484 MHz, then the registers 0xa1f4, 0xa1f8 and 0xa1fc need to be
programmed to the "japan_2484" values.  Conversely, if the current channel
is 2484 MHz and if the channel is changing to one between 2412 and 2472 MHz, then
the three registers need to be programmed to the "normal" values.

This is needed for compliance with Japanese regulatory requirements.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:38 -04:00
Luis R. Rodriguez 990b70ab24 ath9k: move ATH9K_RSSI_BAD to hw.h
mac.c is now core driver independent.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:30 -04:00
Luis R. Rodriguez cfe8cba982 ath9k: clarify what hw code is and remove ath9k.h from a few files
hw code will be shared between ath9k and ath9k_htc.
Just a few more files are left to clean up, mark them as well.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:30 -04:00
Luis R. Rodriguez e3d01bfc3e ath9k: move ATH_AMPDU_LIMIT_MAX to hw.h
This is used by hw code.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:29 -04:00
Luis R. Rodriguez 25c56eec92 ath9k: remove ath9k_ht_macmode
This is used just to determine how to program the MAC,
either for 20 MHz operation of 40 MHz so just use conf_is_ht40()

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:29 -04:00
Luis R. Rodriguez 6420014ca4 ath9k: remove ath9k 25 MHz HT40 spacing stuff
This was for supporting 25 MHz spacing for HT40, this is not used
as we use 20 MHz spacing instead for HT40 as per 802.11n. The hardware
is capable of it though so we leave the phymode definition and EEPROM
parsing for it. If some experimenter wants to work on this stuff stuff
you can add an extension enabling bool on ath_common and perhaps some
debugfs knob to enable it. Keep in mind you'll also need to update the
phymode with the AR_PHY_FC_DYN2040_EXT_CH which has been left on the
driver.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:29 -04:00
Luis R. Rodriguez c46917bb53 atheros: add common debug printing
ath9k uses this for now, ath9k_htc is expected to re-use this
as well. We lave ath5k as is, but it certainly can also be
converted later.

The ath9k module parameter and debugfs entry is kept.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:29 -04:00
Luis R. Rodriguez cd9bf68960 ath9k: separate core driver and hw timer code
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:28 -04:00
Luis R. Rodriguez b002a4a950 atheros: add ieee80211_hw to ath_common
Make use of it on hw code in ath9k to avoid
using the ath9k ath_softc.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:28 -04:00
Luis R. Rodriguez 9e4bffd233 atheros/ath9k: add common read/write ops and port ath9k to use it
In an effort to make hw code driver core agnostic read
and write operations are defined on the ath_common structure.
This patch adds that and makes ath9k use it. This allows
drivers like ath9k_htc to define its own read/write ops and
still rely on the same hw code. This also paves the way for
sharing code between ath9k/ath5k/ath9k_htc.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:27 -04:00
Luis R. Rodriguez 867633f026 ath9k: Define bus agnostic bluetooth coex prep helper
We disable ASPM when enabling bluetooth coexistance. Disabling
ASPM is a bus specific operation. In the future other buses may
support bluetooth coexistance, an example is USB. To this end
move the current routine which disables ASPM into pci.c, and declare
it the PCI bt_coex_prep() helper. Additionally, since ASPM is
a PCI-Express primitive ensure we don't ever try to muck with ASPM
registers on non PCI-express devices.

This also cleans up hw.c to not include bus specific headers or
utilities.

Cc: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Cc: Stephen Chen <stephen.chen@atheros.com>
Cc: Zhifeng Cai <zhifeng.cai@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:27 -04:00
Luis R. Rodriguez 27c51f1a34 ath9k: move ath_common to ath_hw
This ensures that we can access common on hw related code
independent of the driver core.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:26 -04:00
Luis R. Rodriguez 1510718d0f atheros/ath9k: move macaddr, curaid, curbssid and bssidmask to common
These are common amongst ath9k and ath5k, so put them into the
common structure and make ath9k to use it. ar9170 can use macaddr,
and curbssid. We'll change ath5k and ar9170 separately.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:25 -04:00
Luis R. Rodriguez f2b2143e60 ath9k: make ath9k_hw_setbssidmask() and ath9k_hw_write_associd() use ath_hw
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:25 -04:00
Luis R. Rodriguez 9ecdef4be8 ath9k: rename driver core and hw power save helpers
ath9k_hw_setpower_nolock --> ath9k_hw_setpower()
ath9k_hw_setpower() --> ath9k_setpower()

Also change the param for ath9k_setpower() to pass the ath_softc.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:24 -04:00
Luis R. Rodriguez 8c77a5694c ath9k: move ath9k_hw_setpower() to main.c
And we make it static.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:24 -04:00
Luis R. Rodriguez a91d75aec1 ath9k: move ath9k_ps_wakeup() and ath9k_ps_restore() to main.c
These are driver core helpers.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:24 -04:00
Luis R. Rodriguez 766ec4a9a8 ath9k: rename ath_btcoex_info to ath_btcoex_hw
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:22 -04:00
Luis R. Rodriguez 75d7839f4c ath9k: move driver core helpers to main.c
Keep on btcoex.c only hardware access helpers, move the
driver core specific code to main.c. To accomplish
this we had to split ath_init_btcoex_info() into two parts,
the driver core part -- ath_init_btcoex_timer() and the hw
specific part -- ath9k_hw_init_btcoex_hw_info(). This
highlights how ath_gen_timer is part of the driver core, not
hw related, so stuff that into ath_btcoex struct.

The ath9k_hw_btcoex_init() code is now put inline on
ath_init_softc() through a switch to it easier to follow,
since we did that we can now call ath_tx_get_qnum() from
the main.c instead of btcoex.c

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:20 -04:00
Luis R. Rodriguez af03abecd8 ath9k: move hw specific btcoex info to ath_hw
Since we now access it via the ath_hw declare the ath_hw pointer
at the header of some routines and se it. ath9k.h no longer needs to
access btcoex.h and to adjust for this move ath_btcoex_set_weight()
into btcoex.h and instead give main.c a helper for setting initial
values upon drv_start()

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-10-07 16:39:20 -04:00
Sujith d8caa83967 ath9k: Fix chip wakeup issue
Waking up the chip after powering it down fails sometimes.
In this case the CPU is locked for 200ms. Reduce this
interval to 10ms to avoid excessive busy looping.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-23 11:35:51 -04:00
Vivek Natarajan 93b1b37f6a ath9k: Revamp PCIE workarounds
* Disable L1 state ONLY when device is in D3 mode.
* Clear bit 22 of register 0x4004.
* Handle power on/off properly

Not setting the workarounds properly resulted in the
disappearance of the card in certain cases.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-23 11:35:50 -04:00
Vasanthakumar Thiagarajan fe12946e66 ath9k: Enable btcoex based on the subsystem id of the device
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-09 11:25:26 -04:00
Vasanthakumar Thiagarajan aeac355d23 ath9k: Store subsystem id in struct hw_version
This subsystem id will be used later to turn on the btcoex
support.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-09 11:25:25 -04:00
Vasanthakumar Thiagarajan 7b6840ab5f ath9k: Disable ASPM when btcoex is active
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-09 11:18:57 -04:00
Vasanthakumar Thiagarajan 1773912bd2 ath9k: Add Bluetooth Coexistence 3-wire support
This patch adds 3-wire bluetooth coex support for AR9285.
This support can be enabled through btcoex_enable modparam.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:51 -04:00
Vasanthakumar Thiagarajan ff155a45ce ath9k: Add infrastructure for generic hw timers
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:51 -04:00
Vasanthakumar Thiagarajan 81fa16fbe0 ath9k: Remove hw capability bit meant for btcoex
We don't need a hw cap bit for btcoex anymore as btcoex scheme type
is enough to do this.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:51 -04:00
Vasanthakumar Thiagarajan f14462c666 ath9k: Move btcoex related data to a separate struct
Also define macros for wlanactive and btactive (5 & 6) gpios.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:49 -04:00
Vasanthakumar Thiagarajan 17d50d1df4 ath9k: Move btcoex stuff from hw.[ch] to new btcoex.[ch]
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:48 -04:00
Vasanthakumar Thiagarajan f985ad12b5 ath9k: Split ath9k_hw_btcoex_enable() into two logical pieces
This function currently does initialization + enable the
btcoex support. Split it into two logical functions which
does the above operations separately. Btcoex initialization
is done during attach time and enabling this feature is done
in start(). Also, add code to disable btcoex support in stop().

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:48 -04:00
Sujith a13883b0bf ath9k: Reduce the frequency of PA offset calibration
PA calibration need not be done if the offset is not varying.
The current logic does PA calibration even if the offset is the
same.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:46 -04:00