From c93c9ef07c3c27d8ee3d03968f657e4551c9f498 Mon Sep 17 00:00:00 2001
From: Ilan Peer <ilan.peer@intel.com>
Date: Tue, 8 Aug 2017 14:56:58 +0300
Subject: [PATCH 57/68] iwlwifi: mvm: Fix channel switch in case of count <= 1
References: FATE#322675
Patch-mainline: v4.14-rc1
Git-commit: f5d8f50f271d1f80c2afd7eada1c91a863c87a06
The code did not consider the case that the channel switch counter
is <= 1, which would result with an inaccurate calculation of the
time event apply time.
As the specification states that in case of counter == 0 the switch
occurs at any time after the reception the frame, and for counter == 1
the switch would happens before the next TBTT, schedule the time
event immediately.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 850062a89f73..d7feb1ab4dc9 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -3885,11 +3885,16 @@ static int iwl_mvm_pre_channel_switch(struct ieee80211_hw *hw,
/* Schedule the time event to a bit before beacon 1,
* to make sure we're in the new channel when the
- * GO/AP arrives.
+ * GO/AP arrives. In case count <= 1 immediately schedule the
+ * TE (this might result with some packet loss or connection
+ * loss).
*/
- apply_time = chsw->device_timestamp +
- ((vif->bss_conf.beacon_int * (chsw->count - 1) -
- IWL_MVM_CHANNEL_SWITCH_TIME_CLIENT) * 1024);
+ if (chsw->count <= 1)
+ apply_time = 0;
+ else
+ apply_time = chsw->device_timestamp +
+ ((vif->bss_conf.beacon_int * (chsw->count - 1) -
+ IWL_MVM_CHANNEL_SWITCH_TIME_CLIENT) * 1024);
if (chsw->block_tx)
iwl_mvm_csa_client_absent(mvm, vif);
--
2.12.3