1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-calib.c b/drivers/net/wireless/iwlwifi/iwl-calib.c
index 845831ac053e..64de42be7ea3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-calib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-calib.c
@@ -807,6 +807,18 @@ void iwl_chain_noise_calibration(struct iwl_priv *priv,
                 }
         }
 
+        /*
+         * The above algorithm sometimes fails when the ucode
+         * reports 0 for all chains. It's not clear why that
+         * happens to start with, but it is then causing trouble
+         * because this can make us enable more chains than the
+         * hardware really has.
+         *
+         * To be safe, simply mask out any chains that we know
+         * are not on the device.
+         */
+        active_chains &= priv->hw_params.valid_rx_ant;
+
         num_tx_chains = 0;
         for (i = 0; i < NUM_RX_CHAINS; i++) {
                 /* loops on all the bits of