iwlwifi: mvm: don't send GEO_TX_POWER_LIMIT to old firmwares

commit eca1e56 upstream.

Old firmware versions don't support this command. Sending it
to any firmware before -41.ucode will crash the firmware.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=201975

Fixes: 66e8390 ("iwlwifi: fix wrong WGDS_WIFI_DATA_SIZE")
CC: <stable@vger.kernel.org> #4.19+
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: egrumbach

drivers/net/wireless/intel/iwlwifi/mvm/fw.c

@@ -952,6 +952,15 @@ static int iwl_mvm_sar_geo_init(struct iwl_mvm *mvm)
 	int ret, i, j;
 	u16 cmd_wide_id =  WIDE_ID(PHY_OPS_GROUP, GEO_TX_POWER_LIMIT);
 
+	/*
+	 * This command is not supported on earlier firmware versions.
+	 * Unfortunately, we don't have a TLV API flag to rely on, so
+	 * rely on the major version which is in the first byte of
+	 * ucode_ver.
+	 */
+	if (IWL_UCODE_SERIAL(mvm->fw->ucode_ver) < 41)
+		return 0;
+
 	ret = iwl_mvm_sar_get_wgds_table(mvm);
 	if (ret < 0) {
 		IWL_DEBUG_RADIO(mvm,