[PATCH 3.19.y-ckt 107/196] iwlwifi: mvm: don't allow sched scans without matches to be started

[Kamal Mostafa]

3.19.8-ckt16 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Luca Coelho <luciano.coelho at intel.com>

commit 5e56276e7555b34550d51459a801ff75eca8b907 upstream.

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

Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
[ kamal: backport to 3.19-stable: context ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/iwlwifi/mvm/scan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/scan.c b/drivers/net/wireless/iwlwifi/mvm/scan.c
index 844bf7c..9807146 100644
--- a/drivers/net/wireless/iwlwifi/mvm/scan.c
+++ b/drivers/net/wireless/iwlwifi/mvm/scan.c
@@ -1015,6 +1015,10 @@ int iwl_mvm_sched_scan_start(struct iwl_mvm *mvm,
 		.schedule_line[1].full_scan_mul = IWL_FULL_SCAN_MULTIPLIER,
 	};
 
+	/* we don't support "match all" in the firmware */
+	if (!req->n_match_sets)
+		return -EOPNOTSUPP;
+
 	if (iwl_mvm_scan_pass_all(mvm, req))
 		scan_req.flags |= cpu_to_le16(IWL_SCAN_OFFLOAD_FLAG_PASS_ALL);
 
-- 
2.7.0