iwlwifi: don't send GEO_TX_POWER_LIMIT if no wgds table

The GEO_TX_POWER_LIMIT command was sent although
there is no wgds table, so the fw got wrong SAR values
from the driver.

Fix this by avoiding sending the command if no wgds
tables are available.

Signed-off-by: Golan Ben Ami <golan.ben.ami@intel.com>
Fixes: 39c1a97 ("iwlwifi: refactor the SAR tables from mvm to acpi")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Tested-By: Jonathan McDowell <noodles@earth.li>
Tested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200318081237.46db40617cc6.Id5cf852ec8c5dbf20ba86bad7b165a0c828f8b2e@changeid

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

@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2017        Intel Deutschland GmbH
- * Copyright (C) 2019 Intel Corporation
+ * Copyright (C) 2019 - 2020 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -27,7 +27,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2017        Intel Deutschland GmbH
- * Copyright (C) 2019 Intel Corporation
+ * Copyright (C) 2019 - 2020 Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -491,21 +491,21 @@ int iwl_validate_sar_geo_profile(struct iwl_fw_runtime *fwrt,
 }
 IWL_EXPORT_SYMBOL(iwl_validate_sar_geo_profile);
 
-void iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
-		      struct iwl_per_chain_offset_group *table)
+int iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
+		     struct iwl_per_chain_offset_group *table)
 {
 	int ret, i, j;
 
 	if (!iwl_sar_geo_support(fwrt))
-		return;
+		return -EOPNOTSUPP;
 
 	ret = iwl_sar_get_wgds_table(fwrt);
 	if (ret < 0) {
 		IWL_DEBUG_RADIO(fwrt,
 				"Geo SAR BIOS table invalid or unavailable. (%d)\n",
 				ret);
 		/* we don't fail if the table is not available */
-		return;
+		return -ENOENT;
 	}
 
 	BUILD_BUG_ON(ACPI_NUM_GEO_PROFILES * ACPI_WGDS_NUM_BANDS *
@@ -530,5 +530,7 @@ void iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
 					i, j, value[1], value[2], value[0]);
 		}
 	}
+
+	return 0;
 }
 IWL_EXPORT_SYMBOL(iwl_sar_geo_init);

drivers/net/wireless/intel/iwlwifi/fw/acpi.h

@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2017        Intel Deutschland GmbH
- * Copyright(c) 2018 - 2019        Intel Corporation
+ * Copyright(c) 2018 - 2020        Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -27,7 +27,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2017        Intel Deutschland GmbH
- * Copyright(c) 2018 - 2019       Intel Corporation
+ * Copyright(c) 2018 - 2020       Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -171,8 +171,9 @@ bool iwl_sar_geo_support(struct iwl_fw_runtime *fwrt);
 int iwl_validate_sar_geo_profile(struct iwl_fw_runtime *fwrt,
 				 struct iwl_host_cmd *cmd);
 
-void iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
-		      struct iwl_per_chain_offset_group *table);
+int iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
+		     struct iwl_per_chain_offset_group *table);
+
 #else /* CONFIG_ACPI */
 
 static inline void *iwl_acpi_get_object(struct device *dev, acpi_string method)
@@ -243,9 +244,10 @@ static inline int iwl_validate_sar_geo_profile(struct iwl_fw_runtime *fwrt,
 	return -ENOENT;
 }
 
-static inline void iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
-				    struct iwl_per_chain_offset_group *table)
+static inline int iwl_sar_geo_init(struct iwl_fw_runtime *fwrt,
+				   struct iwl_per_chain_offset_group *table)
 {
+	return -ENOENT;
 }
 
 #endif /* CONFIG_ACPI */

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

@@ -762,10 +762,17 @@ static int iwl_mvm_sar_geo_init(struct iwl_mvm *mvm)
 	u16 cmd_wide_id =  WIDE_ID(PHY_OPS_GROUP, GEO_TX_POWER_LIMIT);
 	union geo_tx_power_profiles_cmd cmd;
 	u16 len;
+	int ret;
 
 	cmd.geo_cmd.ops = cpu_to_le32(IWL_PER_CHAIN_OFFSET_SET_TABLES);
 
-	iwl_sar_geo_init(&mvm->fwrt, cmd.geo_cmd.table);
+	ret = iwl_sar_geo_init(&mvm->fwrt, cmd.geo_cmd.table);
+	/*
+	 * It is a valid scenario to not support SAR, or miss wgds table,
+	 * but in that case there is no need to send the command.
+	 */
+	if (ret)
+		return 0;
 
 	cmd.geo_cmd.table_revision = cpu_to_le32(mvm->fwrt.geo_rev);