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ath9k: fix and simplify FFT max index retrieval
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FFT max index retrieval was not retrieved correctly for HT20/HT40 FFT
frames. Fixing the retrieval allows us to remove the fixup function as
well. While at it, split the spectral_max_index function into versions
for ht20 and ht40 to simplify the code.

Cc: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
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Simon Wunderlich authored and Kalle Valo committed Oct 2, 2018
1 parent b796a6c commit 2f85786
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Showing 2 changed files with 23 additions and 39 deletions.
45 changes: 6 additions & 39 deletions drivers/net/wireless/ath/ath9k/common-spectral.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,8 +59,7 @@ ath_cmn_max_idx_verify_ht20_fft(u8 *sample_end, int bytes_read)

sample = sample_end - SPECTRAL_HT20_SAMPLE_LEN + 1;

max_index = spectral_max_index(mag_info->all_bins,
SPECTRAL_HT20_NUM_BINS);
max_index = spectral_max_index_ht20(mag_info->all_bins);
max_magnitude = spectral_max_magnitude(mag_info->all_bins);

max_exp = mag_info->max_exp & 0xf;
Expand Down Expand Up @@ -100,12 +99,10 @@ ath_cmn_max_idx_verify_ht20_40_fft(u8 *sample_end, int bytes_read)
sample = sample_end - SPECTRAL_HT20_40_SAMPLE_LEN + 1;

lower_mag = spectral_max_magnitude(mag_info->lower_bins);
lower_max_index = spectral_max_index(mag_info->lower_bins,
SPECTRAL_HT20_40_NUM_BINS);
lower_max_index = spectral_max_index_ht40(mag_info->lower_bins);

upper_mag = spectral_max_magnitude(mag_info->upper_bins);
upper_max_index = spectral_max_index(mag_info->upper_bins,
SPECTRAL_HT20_40_NUM_BINS);
upper_max_index = spectral_max_index_ht40(mag_info->upper_bins);

max_exp = mag_info->max_exp & 0xf;

Expand All @@ -117,17 +114,6 @@ ath_cmn_max_idx_verify_ht20_40_fft(u8 *sample_end, int bytes_read)
((upper_max_index < 1) || (lower_max_index < 1)))
return -1;

/* Some time hardware messes up the index and adds
* the index of the middle point (dc_pos). Try to fix it.
*/
if ((upper_max_index - dc_pos > 0) &&
(sample[upper_max_index] == (upper_mag >> max_exp)))
upper_max_index -= dc_pos;

if ((lower_max_index - dc_pos > 0) &&
(sample[lower_max_index - dc_pos] == (lower_mag >> max_exp)))
lower_max_index -= dc_pos;

if ((sample[upper_max_index + dc_pos] != (upper_mag >> max_exp)) ||
(sample[lower_max_index] != (lower_mag >> max_exp)))
return -1;
Expand Down Expand Up @@ -169,8 +155,7 @@ ath_cmn_process_ht20_fft(struct ath_rx_status *rs,
magnitude = spectral_max_magnitude(mag_info->all_bins);
fft_sample_20.max_magnitude = __cpu_to_be16(magnitude);

max_index = spectral_max_index(mag_info->all_bins,
SPECTRAL_HT20_NUM_BINS);
max_index = spectral_max_index_ht20(mag_info->all_bins);
fft_sample_20.max_index = max_index;

bitmap_w = spectral_bitmap_weight(mag_info->all_bins);
Expand Down Expand Up @@ -302,12 +287,10 @@ ath_cmn_process_ht20_40_fft(struct ath_rx_status *rs,
upper_mag = spectral_max_magnitude(mag_info->upper_bins);
fft_sample_40.upper_max_magnitude = __cpu_to_be16(upper_mag);

lower_max_index = spectral_max_index(mag_info->lower_bins,
SPECTRAL_HT20_40_NUM_BINS);
lower_max_index = spectral_max_index_ht40(mag_info->lower_bins);
fft_sample_40.lower_max_index = lower_max_index;

upper_max_index = spectral_max_index(mag_info->upper_bins,
SPECTRAL_HT20_40_NUM_BINS);
upper_max_index = spectral_max_index_ht40(mag_info->upper_bins);
fft_sample_40.upper_max_index = upper_max_index;

lower_bitmap_w = spectral_bitmap_weight(mag_info->lower_bins);
Expand All @@ -331,22 +314,6 @@ ath_cmn_process_ht20_40_fft(struct ath_rx_status *rs,
upper_mag >> max_exp,
upper_max_index);

/* Some time hardware messes up the index and adds
* the index of the middle point (dc_pos). Try to fix it.
*/
if ((upper_max_index - dc_pos > 0) &&
(fft_sample_40.data[upper_max_index] == (upper_mag >> max_exp))) {
upper_max_index -= dc_pos;
fft_sample_40.upper_max_index = upper_max_index;
}

if ((lower_max_index - dc_pos > 0) &&
(fft_sample_40.data[lower_max_index - dc_pos] ==
(lower_mag >> max_exp))) {
lower_max_index -= dc_pos;
fft_sample_40.lower_max_index = lower_max_index;
}

/* Check if we got the expected magnitude values at
* the expected bins
*/
Expand Down
17 changes: 17 additions & 0 deletions drivers/net/wireless/ath/ath9k/common-spectral.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -145,6 +145,23 @@ static inline u8 spectral_max_index(u8 *bins, int num_bins)
return m;
}

static inline u8 spectral_max_index_ht40(u8 *bins)
{
u8 idx;

idx = spectral_max_index(bins, SPECTRAL_HT20_40_NUM_BINS);

/* positive values and zero are starting at the beginning
* of the data field.
*/
return idx % (SPECTRAL_HT20_40_NUM_BINS / 2);
}

static inline u8 spectral_max_index_ht20(u8 *bins)
{
return spectral_max_index(bins, SPECTRAL_HT20_NUM_BINS);
}

/* return the bitmap weight from the all/upper/lower bins */
static inline u8 spectral_bitmap_weight(u8 *bins)
{
Expand Down

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