ath9k: add MCS rate index back to debufs rcstat

Speaking of 802.11n rates in terms of Mbps doesn't really developers
and is just useful for users. To aid debugging add the MCS index back
and an HT20/HT40 mode.

New screenshot:

    HT    MCS   Rate    Success    Retries   XRetries        PER
                6.0:          0          0          0          0
                9.0:          0          0          0          0
               12.0:         26        260          0         49
               18.0:         80        804          2         58
               24.0:          0          0          0          0
               36.0:          0          0          0          0
               48.0:          0          0          0          0
               54.0:          0          0          0          0
  HT20      0   6.5:       1368      13660          0         48
  HT20      1  13.0:          0          0          0          0
  HT20      2  19.5:          0          0          0          0
  HT20      3  26.0:          0          0          0          0
  HT20      4  39.0:          0          0          0          0
  HT20      5  52.0:         55        578         14         43
  HT20      6  58.5:         29        306          8         69
  HT20      7  65.0:         21        210          0         67
  HT20      8  13.0:         21        210          0         56
  HT20      9  26.0:          0          0          0          0
  HT20     10  39.0:          0          0          0          0
  HT20     11  52.0:          0          0          0          0
  HT20     12  78.0:          0          0          0          0
  HT20     13 104.0:          0          0          0          0
  HT20     14 117.0:          0          0          0          0
  HT20     15 130.0:         27        290         10         55
  HT40      0  13.5:         79        687         16         17
  HT40      1  27.5:         60        409         10         17
  HT40      2  40.5:         56        381         21         25
  HT40      3  54.0:         44        302         21         18
  HT40      4  81.5:         19        171          2         14
  HT40      5 108.0:          0          0          0          0
  HT40      6 121.5:          0          0          0          0
  HT40      7 135.0:          0          0          0          0
  HT40      7 150.0:          0          0          0          0
  HT40      8  27.0:          0          0          0          0
  HT40      9  54.0:          0          0          0          0
  HT40     10  81.0:          0          0          0          0
  HT40     11 108.0:         11        100          0         18
  HT40     12 162.0:         23        200          0         22
  HT40     13 216.0:         61        580          0         35
  HT40     14 243.0:         37        271          0         66
  HT40     15 270.0:         65        217          2         73
  HT40     15 300.0:          0          0          0          0
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/debug.c

@@ -289,23 +289,49 @@ static ssize_t read_file_rcstat(struct file *file, char __user *user_buf,
 	if (sc->cur_rate_table == NULL)
 		return 0;
 
-	max = 80 + sc->cur_rate_table->rate_cnt * 64;
+	max = 80 + sc->cur_rate_table->rate_cnt * 1024;
 	buf = kmalloc(max + 1, GFP_KERNEL);
 	if (buf == NULL)
 		return 0;
 	buf[max] = 0;
 
-	len += sprintf(buf, "%5s %15s %8s %9s %3s\n\n", "Rate", "Success",
-		       "Retries", "XRetries", "PER");
+	len += sprintf(buf, "%6s %6s %6s "
+		       "%10s %10s %10s %10s\n",
+		       "HT", "MCS", "Rate",
+		       "Success", "Retries", "XRetries", "PER");
 
 	for (i = 0; i < sc->cur_rate_table->rate_cnt; i++) {
 		u32 ratekbps = sc->cur_rate_table->info[i].ratekbps;
 		struct ath_rc_stats *stats = &sc->debug.stats.rcstats[i];
+		char mcs[5];
+		char htmode[5];
+		int used_mcs = 0, used_htmode = 0;
+
+		if (WLAN_RC_PHY_HT(sc->cur_rate_table->info[i].phy)) {
+			used_mcs = snprintf(mcs, 5, "%d",
+				sc->cur_rate_table->info[i].ratecode);
+
+			if (WLAN_RC_PHY_40(sc->cur_rate_table->info[i].phy))
+				used_htmode = snprintf(htmode, 5, "HT40");
+			else if (WLAN_RC_PHY_20(sc->cur_rate_table->info[i].phy))
+				used_htmode = snprintf(htmode, 5, "HT20");
+			else
+				used_htmode = snprintf(htmode, 5, "????");
+		}
+
+		mcs[used_mcs] = '\0';
+		htmode[used_htmode] = '\0';
 
 		len += snprintf(buf + len, max - len,
-			"%3u.%d: %8u %8u %8u %8u\n", ratekbps / 1000,
-			(ratekbps % 1000) / 100, stats->success,
-			stats->retries, stats->xretries,
+			"%6s %6s %3u.%d: "
+			"%10u %10u %10u %10u\n",
+			htmode,
+			mcs,
+			ratekbps / 1000,
+			(ratekbps % 1000) / 100,
+			stats->success,
+			stats->retries,
+			stats->xretries,
 			stats->per);
 	}
 

drivers/net/wireless/ath/ath9k/rc.h

@@ -57,6 +57,10 @@ enum {
 				|| (_phy == WLAN_RC_PHY_HT_40_DS)	\
 				|| (_phy == WLAN_RC_PHY_HT_20_DS_HGI)	\
 				|| (_phy == WLAN_RC_PHY_HT_40_DS_HGI))
+#define WLAN_RC_PHY_20(_phy)   ((_phy == WLAN_RC_PHY_HT_20_SS)		\
+				|| (_phy == WLAN_RC_PHY_HT_20_DS)	\
+				|| (_phy == WLAN_RC_PHY_HT_20_SS_HGI)	\
+				|| (_phy == WLAN_RC_PHY_HT_20_DS_HGI))
 #define WLAN_RC_PHY_40(_phy)   ((_phy == WLAN_RC_PHY_HT_40_SS)		\
 				|| (_phy == WLAN_RC_PHY_HT_40_DS)	\
 				|| (_phy == WLAN_RC_PHY_HT_40_SS_HGI)	\