iwlwifi: mvm: fix and improve printing of rate scale table

Info about VHT/HT rates wasn't printed properly when dumping
the rate scale table. Fix that and print more info. While at it
fix some other minor issues in the printing and prevent
overflowing the print buffer.
Signed-off-by: Eyal Shapira <eyal@wizery.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/rs.c

@@ -2566,13 +2566,75 @@ static ssize_t rs_sta_dbgfs_scale_table_write(struct file *file,
 	return count;
 }
 
+static int rs_pretty_print_rate(char *buf, const u32 rate)
+{
+	static const char * const ant_name[] = {
+		[ANT_NONE] = "None",
+		[ANT_A]    = "A",
+		[ANT_B]    = "B",
+		[ANT_AB]   = "AB",
+		[ANT_C]    = "C",
+		[ANT_AC]   = "AC",
+		[ANT_BC]   = "BC",
+		[ANT_ABC]  = "ABC",
+	};
+
+	char *type, *bw;
+	u8 mcs = 0, nss = 0;
+	u8 ant = (rate & RATE_MCS_ANT_ABC_MSK) >> RATE_MCS_ANT_POS;
+
+	if (!(rate & RATE_MCS_HT_MSK) &&
+	    !(rate & RATE_MCS_VHT_MSK)) {
+		int index = iwl_hwrate_to_plcp_idx(rate);
+
+		return sprintf(buf, "Legacy | ANT: %s Rate: %s Mbps\n",
+			       ant_name[ant], iwl_rate_mcs[index].mbps);
+	}
+
+	if (rate & RATE_MCS_VHT_MSK) {
+		type = "VHT";
+		mcs = rate & RATE_VHT_MCS_RATE_CODE_MSK;
+		nss = ((rate & RATE_VHT_MCS_NSS_MSK)
+		       >> RATE_VHT_MCS_NSS_POS) + 1;
+	} else if (rate & RATE_MCS_HT_MSK) {
+		type = "HT";
+		mcs = rate & RATE_HT_MCS_INDEX_MSK;
+	} else {
+		type = "Unknown"; /* shouldn't happen */
+	}
+
+	switch (rate & RATE_MCS_CHAN_WIDTH_MSK) {
+	case RATE_MCS_CHAN_WIDTH_20:
+		bw = "20Mhz";
+		break;
+	case RATE_MCS_CHAN_WIDTH_40:
+		bw = "40Mhz";
+		break;
+	case RATE_MCS_CHAN_WIDTH_80:
+		bw = "80Mhz";
+		break;
+	case RATE_MCS_CHAN_WIDTH_160:
+		bw = "160Mhz";
+		break;
+	default:
+		bw = "BAD BW";
+	}
+
+	return sprintf(buf, "%s | ANT: %s BW: %s MCS: %d NSS: %d %s%s%s%s%s\n",
+		       type, ant_name[ant], bw, mcs, nss,
+		       (rate & RATE_MCS_SGI_MSK) ? "SGI " : "NGI ",
+		       (rate & RATE_MCS_STBC_MSK) ? "STBC " : "",
+		       (rate & RATE_MCS_LDPC_MSK) ? "LDPC " : "",
+		       (rate & RATE_MCS_BF_MSK) ? "BF " : "",
+		       (rate & RATE_MCS_ZLF_MSK) ? "ZLF " : "");
+}
+
 static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 			char __user *user_buf, size_t count, loff_t *ppos)
 {
 	char *buff;
 	int desc = 0;
 	int i = 0;
-	int index = 0;
 	ssize_t ret;
 
 	struct iwl_lq_sta *lq_sta = file->private_data;
@@ -2580,7 +2642,7 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
 
 	mvm = lq_sta->drv;
-	buff = kmalloc(1024, GFP_KERNEL);
+	buff = kmalloc(2048, GFP_KERNEL);
 	if (!buff)
 		return -ENOMEM;
 
@@ -2597,7 +2659,7 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 	desc += sprintf(buff+desc, "lq type %s\n",
 			(is_legacy(tbl->lq_type)) ? "legacy" :
 			is_vht(tbl->lq_type) ? "VHT" : "HT");
-	if (is_ht(tbl->lq_type)) {
+	if (!is_legacy(tbl->lq_type)) {
 		desc += sprintf(buff+desc, " %s",
 		   (is_siso(tbl->lq_type)) ? "SISO" : "MIMO2");
 		   desc += sprintf(buff+desc, " %s",
@@ -2605,13 +2667,13 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 				   (is_ht40(tbl)) ? "40MHz" :
 				   (is_ht80(tbl)) ? "80Mhz" : "BAD BW");
 		   desc += sprintf(buff+desc, " %s %s\n",
-				   (tbl->is_SGI) ? "SGI" : "",
+				   (tbl->is_SGI) ? "SGI" : "NGI",
 				   (lq_sta->is_agg) ? "AGG on" : "");
 	}
 	desc += sprintf(buff+desc, "last tx rate=0x%X\n",
 			lq_sta->last_rate_n_flags);
 	desc += sprintf(buff+desc,
-			"general: flags=0x%X mimo-d=%d s-ant0x%x d-ant=0x%x\n",
+			"general: flags=0x%X mimo-d=%d s-ant=0x%x d-ant=0x%x\n",
 			lq_sta->lq.flags,
 			lq_sta->lq.mimo_delim,
 			lq_sta->lq.single_stream_ant_msk,
@@ -2631,19 +2693,12 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 			lq_sta->lq.initial_rate_index[3]);
 
 	for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++) {
-		index = iwl_hwrate_to_plcp_idx(
-			le32_to_cpu(lq_sta->lq.rs_table[i]));
-		if (is_legacy(tbl->lq_type)) {
-			desc += sprintf(buff+desc, " rate[%d] 0x%X %smbps\n",
-					i, le32_to_cpu(lq_sta->lq.rs_table[i]),
-					iwl_rate_mcs[index].mbps);
-		} else {
-			desc += sprintf(buff+desc,
-					" rate[%d] 0x%X %smbps (%s)\n",
-					i, le32_to_cpu(lq_sta->lq.rs_table[i]),
-					iwl_rate_mcs[index].mbps,
-					iwl_rate_mcs[index].mcs);
-		}
+		u32 rate = le32_to_cpu(lq_sta->lq.rs_table[i]);
+		desc += sprintf(buff+desc,
+				" rate[%d] 0x%X ",
+				i, rate);
+
+		desc += rs_pretty_print_rate(buff+desc, rate);
 	}
 
 	ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);