iwlwifi: mvm: don't send GEO_TX_POWER_LIMIT on version < 41

Firmware versions before 41 don't support the GEO_TX_POWER_LIMIT
command, and sending it to the firmware will cause a firmware crash.
We allow this via debugfs, so we need to return an error value in case
it's not supported.

This had already been fixed during init, when we send the command if
the ACPI WGDS table is present.  Fix it also for the other,
userspace-triggered case.

Cc: stable@vger.kernel.org
Fixes: 7fe90e0e ("iwlwifi: mvm: refactor geo init")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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

@@ -880,6 +880,17 @@ int iwl_mvm_sar_select_profile(struct iwl_mvm *mvm, int prof_a, int prof_b)
 	return iwl_mvm_send_cmd_pdu(mvm, REDUCE_TX_POWER_CMD, 0, len, &cmd);
 }
 
+static bool iwl_mvm_sar_geo_support(struct iwl_mvm *mvm)
+{
+	/*
+	 * The GEO_TX_POWER_LIMIT 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.
+	 */
+	return IWL_UCODE_SERIAL(mvm->fw->ucode_ver) >= 41;
+}
+
 int iwl_mvm_get_sar_geo_profile(struct iwl_mvm *mvm)
 {
 	struct iwl_geo_tx_power_profiles_resp *resp;
@@ -909,6 +920,9 @@ int iwl_mvm_get_sar_geo_profile(struct iwl_mvm *mvm)
 		.data = { data },
 	};
 
+	if (!iwl_mvm_sar_geo_support(mvm))
+		return -EOPNOTSUPP;
+
 	ret = iwl_mvm_send_cmd(mvm, &cmd);
 	if (ret) {
 		IWL_ERR(mvm, "Failed to get geographic profile info %d\n", ret);
@@ -934,13 +948,7 @@ 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)
+	if (!iwl_mvm_sar_geo_support(mvm))
 		return 0;
 
 	ret = iwl_mvm_sar_get_wgds_table(mvm);