iwlwifi: mvm: avoid searching unnecessary columns

Don't search columns which are unlikely to succeed as previous
columns searched with less aggressive modulation failed.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: Eyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

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

@@ -212,8 +212,8 @@ static const struct rs_tx_column rs_tx_columns[] = {
 			RS_COLUMN_LEGACY_ANT_B,
 			RS_COLUMN_SISO_ANT_A,
 			RS_COLUMN_SISO_ANT_B,
-			RS_COLUMN_MIMO2,
-			RS_COLUMN_MIMO2_SGI,
+			RS_COLUMN_INVALID,
+			RS_COLUMN_INVALID,
 			RS_COLUMN_INVALID,
 			RS_COLUMN_INVALID,
 		},
@@ -225,8 +225,8 @@ static const struct rs_tx_column rs_tx_columns[] = {
 			RS_COLUMN_LEGACY_ANT_A,
 			RS_COLUMN_SISO_ANT_A,
 			RS_COLUMN_SISO_ANT_B,
-			RS_COLUMN_MIMO2,
-			RS_COLUMN_MIMO2_SGI,
+			RS_COLUMN_INVALID,
+			RS_COLUMN_INVALID,
 			RS_COLUMN_INVALID,
 			RS_COLUMN_INVALID,
 		},
@@ -239,9 +239,9 @@ static const struct rs_tx_column rs_tx_columns[] = {
 			RS_COLUMN_MIMO2,
 			RS_COLUMN_SISO_ANT_A_SGI,
 			RS_COLUMN_SISO_ANT_B_SGI,
-			RS_COLUMN_MIMO2_SGI,
 			RS_COLUMN_LEGACY_ANT_A,
 			RS_COLUMN_LEGACY_ANT_B,
+			RS_COLUMN_INVALID,
 		},
 		.checks = {
 			rs_siso_allow,
@@ -255,9 +255,9 @@ static const struct rs_tx_column rs_tx_columns[] = {
 			RS_COLUMN_MIMO2,
 			RS_COLUMN_SISO_ANT_B_SGI,
 			RS_COLUMN_SISO_ANT_A_SGI,
-			RS_COLUMN_MIMO2_SGI,
 			RS_COLUMN_LEGACY_ANT_A,
 			RS_COLUMN_LEGACY_ANT_B,
+			RS_COLUMN_INVALID,
 		},
 		.checks = {
 			rs_siso_allow,