[PATCH] ath10k: Add support to configure channel dwell time

[Pradeep Kumar Chitrapu]

Configure channel dwell time from duration of the scan request
received from mac80211 when the duration is non-zero. When the
scan request does not have duration value, use the default ones,
the current implementation.

Corresponding flag NL80211_EXT_FEATURE_SET_SCAN_DWELL is
advertized.

Supported Chipsets:
 -QCA988X/QCA9887 PCI
 -QCA99X0/QCA9984/QCA9888/QCA4019 PCI
 -QCA6174/QCA9377 PCI/USB/SDIO
 -WCN3990 SNOC

Tested on QCA9984 with firmware ver 10.4-3.6-0010

Signed-off-by: Pradeep Kumar Chitrapu <prade...@codeaurora.org>
---
 drivers/net/wireless/ath/ath10k/core.h |  1 +
 drivers/net/wireless/ath/ath10k/mac.c  | 23 ++++++++++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.h 
b/drivers/net/wireless/ath/ath10k/core.h
index c17d805..39d4d7d 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -44,6 +44,7 @@
 #define WO(_f)      ((_f##_OFFSET) >> 2)
 
 #define ATH10K_SCAN_ID 0
+#define ATH10K_SCAN_CHANNEL_SWITCH_WMI_EVT_OVERHEAD 10 /* msec */
 #define WMI_READY_TIMEOUT (5 * HZ)
 #define ATH10K_FLUSH_TIMEOUT_HZ (5 * HZ)
 #define ATH10K_CONNECTION_LOSS_HZ (3 * HZ)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c 
b/drivers/net/wireless/ath/ath10k/mac.c
index bf05a36..c6828c7 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5668,6 +5668,7 @@ static int ath10k_hw_scan(struct ieee80211_hw *hw,
        struct wmi_start_scan_arg arg;
        int ret = 0;
        int i;
+       u32 scan_timeout;
 
        mutex_lock(&ar->conf_mutex);
 
@@ -5723,6 +5724,22 @@ static int ath10k_hw_scan(struct ieee80211_hw *hw,
                        arg.channels[i] = req->channels[i]->center_freq;
        }
 
+       /* if duration is set, default dwell times will be overwritten */
+       if (req->duration) {
+               arg.dwell_time_active = req->duration;
+               arg.dwell_time_passive = req->duration;
+               arg.burst_duration_ms = req->duration;
+
+               scan_timeout = min_t(u32, arg.max_rest_time *
+                               (arg.n_channels - 1) + (req->duration +
+                               ATH10K_SCAN_CHANNEL_SWITCH_WMI_EVT_OVERHEAD) *
+                               arg.n_channels, arg.max_scan_time + 200);
+
+       } else {
+               /* Add a 200ms margin to account for event/command processing */
+               scan_timeout = arg.max_scan_time + 200;
+       }
+
        ret = ath10k_start_scan(ar, &arg);
        if (ret) {
                ath10k_warn(ar, "failed to start hw scan: %d\n", ret);
@@ -5731,10 +5748,8 @@ static int ath10k_hw_scan(struct ieee80211_hw *hw,
                spin_unlock_bh(&ar->data_lock);
        }
 
-       /* Add a 200ms margin to account for event/command processing */
        ieee80211_queue_delayed_work(ar->hw, &ar->scan.timeout,
-                                    msecs_to_jiffies(arg.max_scan_time +
-                                                     200));
+                                    msecs_to_jiffies(scan_timeout));
 
 exit:
        mutex_unlock(&ar->conf_mutex);
@@ -8351,6 +8366,8 @@ int ath10k_mac_register(struct ath10k *ar)
        }
 
        wiphy_ext_feature_set(ar->hw->wiphy, NL80211_EXT_FEATURE_VHT_IBSS);
+       wiphy_ext_feature_set(ar->hw->wiphy,
+                             NL80211_EXT_FEATURE_SET_SCAN_DWELL);
 
        /*
         * on LL hardware queues are managed entirely by the FW
-- 
1.9.1