I/Q calibration was completely broken, resulting in a high number of CRC errors
on received packets. before i could see around 10% to 20% CRC errors, with this
patch they are between 0% and 3%.
1.) the removal of the mask in commit "ath5k: Fix I/Q calibration
(f1cf2dbd0f)" resulted in no mask beeing used
when writing the I/Q values into the register. additional errors in the
calculation of the values (see 2.) resulted too high numbers, exceeding the
masks, so wrong values like 0xfffffffe were written. to be safe we should
always use the bitmask when writing parts of a register.
2.) using a (s32) cast for q_coff is a wrong conversion to signed, since we
convert to a signed value later by substracting 128. this resulted in too low
numbers for Q many times, which were limited to -16 by the boundary check later
on.
3.) checked everything against the HAL sources and took over comments and minor
optimizations from there.
4.) we can't use ENABLE_BITS when we want to write a number (the number can
contain zeros). also always write the correction values first and set ENABLE
bit last, like the HAL does.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Cc: stable@kernel.org
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This updates ath5k to calibrate the noise floor similar to the
way it is done in the madwifi hal and ath9k. Of note:
- we start NF measurement at the same time as AGC calibration,
but do not actually read the value until the periodic (long)
calibration
- we keep a history of the last few values read and write the
median back to the hardware for CCA
- we do not complain if NF calibration isn't complete, instead
we keep the last read value.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Also make ath5k and ath9k use it, and share register definitions.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The new values are taken from the recently open sourced Atheros HAL.
Correctness is also confirmed by the users with access to Atheros
documentation.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
* Add code to support the various antenna scenarios supported by hw
* For now hardcode the default scenario (single or dual omnis with
tx/rx diversity working and tx antenna handled by session -hw keeps
track on which antenna it got ack from each ap/station and maps each
ap/station to one of the antennas-).
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
