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| author | Bruno Randolf <br1@einfach.org> | 2010-03-09 16:56:05 +0900 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-03-10 16:16:56 -0500 |
| commit | 86415d43efd4f7093979cfa8a80232114266f1a4 (patch) | |
| tree | 47af91f1bccde944f86a77b8fdb586e1877c9af7 /drivers/net/wireless/ath/ath5k/reg.h | |
| parent | a3b980fd1391e75068ae25f3817728b27bfdb04c (diff) | |
| download | lwn-86415d43efd4f7093979cfa8a80232114266f1a4.tar.gz lwn-86415d43efd4f7093979cfa8a80232114266f1a4.zip | |
ath5k: fix I/Q calibration (for real)
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
(f1cf2dbd0f798b71b1590e7aca6647f2caef1649)" 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>
Diffstat (limited to 'drivers/net/wireless/ath/ath5k/reg.h')
| -rw-r--r-- | drivers/net/wireless/ath/ath5k/reg.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath5k/reg.h b/drivers/net/wireless/ath/ath5k/reg.h index 4cb9c5df9f46..1464f89b249c 100644 --- a/drivers/net/wireless/ath/ath5k/reg.h +++ b/drivers/net/wireless/ath/ath5k/reg.h @@ -2187,6 +2187,7 @@ */ #define AR5K_PHY_IQ 0x9920 /* Register Address */ #define AR5K_PHY_IQ_CORR_Q_Q_COFF 0x0000001f /* Mask for q correction info */ +#define AR5K_PHY_IQ_CORR_Q_Q_COFF_S 0 #define AR5K_PHY_IQ_CORR_Q_I_COFF 0x000007e0 /* Mask for i correction info */ #define AR5K_PHY_IQ_CORR_Q_I_COFF_S 5 #define AR5K_PHY_IQ_CORR_ENABLE 0x00000800 /* Enable i/q correction */ |