ath9k: Skip malformed frames on normal FFT report

Since we have lots of frames on a normal FFT report don't bother
processing the malformed ones. Only try to fix malformed frames
in case of a short FFT report (only a single frame on the report).

Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
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 51ab3961443f4a402e1731366ecc74e27136e37d..0c9bc9ea5d9d6153901433ed5cbdb012309c2104 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/common-spectral.c
+++ b/drivers/net/wireless/ath/ath9k/common-spectral.c
@@ -437,6 +437,42 @@ ath_cmn_process_ht20_40_fft(struct ath_rx_status *rs,
        return 0;
 }
 
+static inline void
+ath_cmn_copy_fft_frame(u8 *in, u8 *out, int sample_len, int sample_bytes)
+{
+       switch (sample_bytes - sample_len) {
+       case -1:
+               /* First byte missing */
+               memcpy(&out[1], in,
+                      sample_len - 1);
+               break;
+       case 0:
+               /* Length correct, nothing to do. */
+               memcpy(out, in, sample_len);
+               break;
+       case 1:
+               /* MAC added 2 extra bytes AND first byte
+                * is missing.
+                */
+               memcpy(&out[1], in, 30);
+               out[31] = in[31];
+               memcpy(&out[32], &in[33],
+                      sample_len - 32);
+               break;
+       case 2:
+               /* MAC added 2 extra bytes at bin 30 and 32,
+                * remove them.
+                */
+               memcpy(out, in, 30);
+               out[30] = in[31];
+               memcpy(&out[31], &in[33],
+                      sample_len - 31);
+               break;
+       default:
+               break;
+       }
+}
+
 /* returns 1 if this was a spectral frame, even if not handled. */
 int ath_cmn_process_fft(struct ath_spec_scan_priv *spec_priv, struct ieee80211_hdr *hdr,
                    struct ath_rx_status *rs, u64 tsf)
@@ -570,46 +606,40 @@ int ath_cmn_process_fft(struct ath_spec_scan_priv *spec_priv, struct ieee80211_h
                if (got_slen) {
                        ath_dbg(common, SPECTRAL_SCAN, "FFT frame len: %i\n",
                                sample_bytes);
-                       switch (sample_bytes - sample_len) {
-                       case -1:
-                               /* First byte missing */
-                               memcpy(&sample_buf[1], sample_start,
-                                      sample_len - 1);
-                               break;
-                       case 0:
-                               /* Length correct, nothing to do. */
+
+                       /* Only try to fix a frame if it's the only one
+                        * on the report, else just skip it.
+                        */
+                       if (sample_bytes != sample_len && len <= fft_len + 2) {
+                               ath_cmn_copy_fft_frame(sample_start,
+                                                      sample_buf, sample_len,
+                                                      sample_bytes);
+
+                               fft_handler(rs, spec_priv, sample_buf,
+                                           tsf, freq, chan_type);
+                       }
+
+                       /* Process a normal frame */
+                       if (sample_bytes == sample_len) {
                                memcpy(sample_buf, sample_start, sample_len);
-                               break;
-                       case 1:
-                               /* MAC added 2 extra bytes AND first byte
-                                * is missing.
-                                */
-                               memcpy(&sample_buf[1], sample_start, 30);
-                               sample_buf[31] = sample_start[31];
-                               memcpy(&sample_buf[32], &sample_start[33],
-                                      sample_len - 32);
-                               break;
-                       case 2:
-                               /* MAC added 2 extra bytes at bin 30 and 32,
-                                * remove them.
-                                */
-                               memcpy(sample_buf, sample_start, 30);
-                               sample_buf[30] = sample_start[31];
-                               memcpy(&sample_buf[31], &sample_start[33],
-                                      sample_len - 31);
-                               break;
-                       default:
-                               break;
+                               ret = fft_handler(rs, spec_priv, sample_buf,
+                                                 tsf, freq, chan_type);
                        }
 
-                       ret = fft_handler(rs, spec_priv, sample_buf, tsf,
-                                                       freq, chan_type);
+                       /* Short report processed, break out of the
+                        * loop.
+                        */
+                       if (len <= fft_len + 2)
+                               break;
+
                        memset(sample_buf, 0, SPECTRAL_SAMPLE_MAX_LEN);
                        sample_start = &vdata[i + 1];
+
                        /* -1 to grab sample_len -1, -2 since
                         * they 'll get increased by one. In case
                         * of failure try to recover by going byte
-                        * by byte instead. */
+                        * by byte instead.
+                        */
                        if (ret == 0) {
                                i += num_bins - 2;
                                sample_bytes = num_bins - 2;