iwlwifi: mvm: don't allow sched scans without matches to be started

The firmware can perform a scheduled scan with not matchsets passed,
but it can't send notification that results were found.  Since the
userspace then cannot know when we got new results and the firmware
wouldn't trigger a wake in case we are sleeping, it's better not to
allow scans without matchsets.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=110831

Cc: <stable@vger.kernel.org> [3.17+]
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
index 9a15642f80dd28b88dc4ae8326f465a7ec583e35..ea1e177c2ea101463a43a1c73b7dfb995dc9b135 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
@@ -1298,6 +1298,10 @@ int iwl_mvm_sched_scan_start(struct iwl_mvm *mvm,
                return -EBUSY;
        }
 
+       /* we don't support "match all" in the firmware */
+       if (!req->n_match_sets)
+               return -EOPNOTSUPP;
+
        ret = iwl_mvm_check_running_scans(mvm, type);
        if (ret)
                return ret;