ath9k: fix and simplify FFT max index retrieval

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>

diff --git a/drivers/net/wireless/ath/ath9k/common-spectral.c b/drivers/net/wireless/ath/ath9k/common-spectral.c
index f6dd0ecfbbf3316170becae534ef4cf7f79f6f1a..d10e3f29c3562b87e6d17a80df71f4a610fd0d9d 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/common-spectral.c
+++ b/drivers/net/wireless/ath/ath9k/common-spectral.c
@@ -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;
@@ -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;
 
@@ -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;
@@ -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);
@@ -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);
@@ -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
         */

diff --git a/drivers/net/wireless/ath/ath9k/common-spectral.h b/drivers/net/wireless/ath/ath9k/common-spectral.h
index 303ab470ce34b6d92efaade5492ddd2515ccfdd2..011d8ab8b9744610d89dc809449ea5b99cd86fae 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/common-spectral.h
+++ b/drivers/net/wireless/ath/ath9k/common-spectral.h
@@ -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)
 {