[PATCH] iwlwifi: mvm: Avoid use of GEO_TX_POWER_LIMIT when not supported

From: Jonathan McDowell
Date: Sun Mar 15 2020 - 05:27:36 EST


Commit 39c1a9728f93 refactored the SAR table support and inadvertently
added a call to GEO_TX_POWER_LIMIT without checking that the firmware
supported it. This caused a regression for device + firmware
combinations lacking the support. Add a check in iwl_mvm_sar_init to
prevent this.

Fixes: 39c1a9728f93 (iwlwifi: refactor the SAR tables from mvm to acpi)
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206395
Cc: stable@xxxxxxxxxxxxxxx # 5.5
Signed-Off-By: Jonathan McDowell <noodles@xxxxxxxx>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
index 54c094e88474..4a8a4cb2c553 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -1007,6 +1007,13 @@ static int iwl_mvm_sar_init(struct iwl_mvm *mvm)
if (ret == -ENOENT)
return 1;

+ /*
+ * If our firmware doesn't support GEO_TX_POWER_LIMIT then skip trying
+ * to use it.
+ */
+ if (!iwl_sar_geo_support(&mvm->fwrt))
+ return 1;
+
return ret;
}


--
... Don't do it!