[PATCH v2 2/2] wcn36xx: Implement firmware assisted scan

From: Bjorn Andersson
Date: Fri Aug 12 2016 - 20:18:01 EST

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Using the software based channel scan mechanism from mac80211 keeps us
offline for 10-15 second, we should instead issue a start_scan/end_scan
on each channel reducing this time.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

It's been a while since I posted this as an RFC, I have not received any
comments on the code but we've been running it in the Linaro kernel with good
results and possitive user feedback for quite some time.

So I'm hoping we can merge it, as it solves the #1 complaint we had with users;
where NetworkManager (or something similar) would stall and time out their
connections by scanning for networks every now and then.

drivers/net/wireless/ath/wcn36xx/main.c | 62 ++++++++++++++++++++++++------
drivers/net/wireless/ath/wcn36xx/smd.c | 8 ++--
drivers/net/wireless/ath/wcn36xx/smd.h | 4 +-
drivers/net/wireless/ath/wcn36xx/txrx.c | 19 ++++++---
drivers/net/wireless/ath/wcn36xx/wcn36xx.h | 9 +++++
5 files changed, 79 insertions(+), 23 deletions(-)

diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
index 3c2522b07c90..23650b24c5bf 100644
--- a/drivers/net/wireless/ath/wcn36xx/main.c
+++ b/drivers/net/wireless/ath/wcn36xx/main.c
@@ -568,23 +568,57 @@ out:
return ret;
}

-static void wcn36xx_sw_scan_start(struct ieee80211_hw *hw,
- struct ieee80211_vif *vif,
- const u8 *mac_addr)
+static void wcn36xx_hw_scan_worker(struct work_struct *work)
{
- struct wcn36xx *wcn = hw->priv;
+ struct wcn36xx *wcn = container_of(work, struct wcn36xx, scan_work);
+ struct cfg80211_scan_request *req = wcn->scan_req;
+ u8 channels[WCN36XX_HAL_PNO_MAX_NETW_CHANNELS_EX];
+ int i;
+
+ wcn36xx_dbg(WCN36XX_DBG_MAC, "mac80211 scan %d channels worker\n", req->n_channels);
+
+ for (i = 0; i < req->n_channels; i++)
+ channels[i] = req->channels[i]->hw_value;
+
+ wcn36xx_smd_update_scan_params(wcn, channels, req->n_channels);

wcn36xx_smd_init_scan(wcn, HAL_SYS_MODE_SCAN);
- wcn36xx_smd_start_scan(wcn);
+ for (i = 0; i < req->n_channels; i++) {
+ wcn->scan_freq = req->channels[i]->center_freq;
+ wcn->scan_band = req->channels[i]->band;
+
+ wcn36xx_smd_start_scan(wcn, req->channels[i]->hw_value);
+ msleep(30);
+ wcn36xx_smd_end_scan(wcn, req->channels[i]->hw_value);
+
+ wcn->scan_freq = 0;
+ }
+ wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN);
+
+ ieee80211_scan_completed(wcn->hw, false);
+
+ mutex_lock(&wcn->scan_lock);
+ wcn->scan_req = NULL;
+ mutex_unlock(&wcn->scan_lock);
}

-static void wcn36xx_sw_scan_complete(struct ieee80211_hw *hw,
- struct ieee80211_vif *vif)
+static int wcn36xx_hw_scan(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_scan_request *hw_req)
{
struct wcn36xx *wcn = hw->priv;

- wcn36xx_smd_end_scan(wcn);
- wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN);
+ mutex_lock(&wcn->scan_lock);
+ if (wcn->scan_req) {
+ mutex_unlock(&wcn->scan_lock);
+ return -EBUSY;
+ }
+ wcn->scan_req = &hw_req->req;
+ mutex_unlock(&wcn->scan_lock);
+
+ schedule_work(&wcn->scan_work);
+
+ return 0;
}

static void wcn36xx_update_allowed_rates(struct ieee80211_sta *sta,
@@ -997,8 +1031,7 @@ static const struct ieee80211_ops wcn36xx_ops = {
.configure_filter = wcn36xx_configure_filter,
.tx = wcn36xx_tx,
.set_key = wcn36xx_set_key,
- .sw_scan_start = wcn36xx_sw_scan_start,
- .sw_scan_complete = wcn36xx_sw_scan_complete,
+ .hw_scan = wcn36xx_hw_scan,
.bss_info_changed = wcn36xx_bss_info_changed,
.set_rts_threshold = wcn36xx_set_rts_threshold,
.sta_add = wcn36xx_sta_add,
@@ -1023,6 +1056,7 @@ static int wcn36xx_init_ieee80211(struct wcn36xx *wcn)
ieee80211_hw_set(wcn->hw, SUPPORTS_PS);
ieee80211_hw_set(wcn->hw, SIGNAL_DBM);
ieee80211_hw_set(wcn->hw, HAS_RATE_CONTROL);
+ ieee80211_hw_set(wcn->hw, SINGLE_SCAN_ON_ALL_BANDS);

wcn->hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
BIT(NL80211_IFTYPE_AP) |
@@ -1032,6 +1066,9 @@ static int wcn36xx_init_ieee80211(struct wcn36xx *wcn)
wcn->hw->wiphy->bands[NL80211_BAND_2GHZ] = &wcn_band_2ghz;
wcn->hw->wiphy->bands[NL80211_BAND_5GHZ] = &wcn_band_5ghz;

+ wcn->hw->wiphy->max_scan_ssids = WCN36XX_MAX_SCAN_SSIDS;
+ wcn->hw->wiphy->max_scan_ie_len = WCN36XX_MAX_SCAN_IE_LEN;
+
wcn->hw->wiphy->cipher_suites = cipher_suites;
wcn->hw->wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);

@@ -1152,6 +1189,9 @@ static int wcn36xx_probe(struct platform_device *pdev)
wcn->hw = hw;
wcn->dev = &pdev->dev;
mutex_init(&wcn->hal_mutex);
+ mutex_init(&wcn->scan_lock);
+
+ INIT_WORK(&wcn->scan_work, wcn36xx_hw_scan_worker);

wcn->smd_channel = qcom_wcnss_open_channel(wcnss, "WLAN_CTRL", wcn36xx_smd_rsp_process);
if (IS_ERR(wcn->smd_channel)) {
diff --git a/drivers/net/wireless/ath/wcn36xx/smd.c b/drivers/net/wireless/ath/wcn36xx/smd.c
index d9ff2e2a8118..83d067876969 100644
--- a/drivers/net/wireless/ath/wcn36xx/smd.c
+++ b/drivers/net/wireless/ath/wcn36xx/smd.c
@@ -522,7 +522,7 @@ out:
return ret;
}

-int wcn36xx_smd_start_scan(struct wcn36xx *wcn)
+int wcn36xx_smd_start_scan(struct wcn36xx *wcn, u8 scan_channel)
{
struct wcn36xx_hal_start_scan_req_msg msg_body;
int ret = 0;
@@ -530,7 +530,7 @@ int wcn36xx_smd_start_scan(struct wcn36xx *wcn)
mutex_lock(&wcn->hal_mutex);
INIT_HAL_MSG(msg_body, WCN36XX_HAL_START_SCAN_REQ);

- msg_body.scan_channel = WCN36XX_HW_CHANNEL(wcn);
+ msg_body.scan_channel = scan_channel;

PREPARE_HAL_BUF(wcn->hal_buf, msg_body);

@@ -552,7 +552,7 @@ out:
return ret;
}

-int wcn36xx_smd_end_scan(struct wcn36xx *wcn)
+int wcn36xx_smd_end_scan(struct wcn36xx *wcn, u8 scan_channel)
{
struct wcn36xx_hal_end_scan_req_msg msg_body;
int ret = 0;
@@ -560,7 +560,7 @@ int wcn36xx_smd_end_scan(struct wcn36xx *wcn)
mutex_lock(&wcn->hal_mutex);
INIT_HAL_MSG(msg_body, WCN36XX_HAL_END_SCAN_REQ);

- msg_body.scan_channel = WCN36XX_HW_CHANNEL(wcn);
+ msg_body.scan_channel = scan_channel;

PREPARE_HAL_BUF(wcn->hal_buf, msg_body);

diff --git a/drivers/net/wireless/ath/wcn36xx/smd.h b/drivers/net/wireless/ath/wcn36xx/smd.h
index 40d829563c2b..8892ccd67b14 100644
--- a/drivers/net/wireless/ath/wcn36xx/smd.h
+++ b/drivers/net/wireless/ath/wcn36xx/smd.h
@@ -60,8 +60,8 @@ int wcn36xx_smd_load_nv(struct wcn36xx *wcn);
int wcn36xx_smd_start(struct wcn36xx *wcn);
int wcn36xx_smd_stop(struct wcn36xx *wcn);
int wcn36xx_smd_init_scan(struct wcn36xx *wcn, enum wcn36xx_hal_sys_mode mode);
-int wcn36xx_smd_start_scan(struct wcn36xx *wcn);
-int wcn36xx_smd_end_scan(struct wcn36xx *wcn);
+int wcn36xx_smd_start_scan(struct wcn36xx *wcn, u8 scan_channel);
+int wcn36xx_smd_end_scan(struct wcn36xx *wcn, u8 scan_channel);
int wcn36xx_smd_finish_scan(struct wcn36xx *wcn,
enum wcn36xx_hal_sys_mode mode);
int wcn36xx_smd_update_scan_params(struct wcn36xx *wcn, u8 *channels, size_t channel_count);
diff --git a/drivers/net/wireless/ath/wcn36xx/txrx.c b/drivers/net/wireless/ath/wcn36xx/txrx.c
index 1f34c2e912d7..8c387a0a3c09 100644
--- a/drivers/net/wireless/ath/wcn36xx/txrx.c
+++ b/drivers/net/wireless/ath/wcn36xx/txrx.c
@@ -45,9 +45,20 @@ int wcn36xx_rx_skb(struct wcn36xx *wcn, struct sk_buff *skb)
skb_put(skb, bd->pdu.mpdu_header_off + bd->pdu.mpdu_len);
skb_pull(skb, bd->pdu.mpdu_header_off);

+ hdr = (struct ieee80211_hdr *) skb->data;
+ fc = __le16_to_cpu(hdr->frame_control);
+ sn = IEEE80211_SEQ_TO_SN(__le16_to_cpu(hdr->seq_ctrl));
+
+ /* When scanning associate beacons to this */
+ if (ieee80211_is_beacon(hdr->frame_control) && wcn->scan_freq) {
+ status.freq = wcn->scan_freq;
+ status.band = wcn->scan_band;
+ } else {
+ status.freq = WCN36XX_CENTER_FREQ(wcn);
+ status.band = WCN36XX_BAND(wcn);
+ }
+
status.mactime = 10;
- status.freq = WCN36XX_CENTER_FREQ(wcn);
- status.band = WCN36XX_BAND(wcn);
status.signal = -get_rssi0(bd);
status.antenna = 1;
status.rate_idx = 1;
@@ -61,10 +72,6 @@ int wcn36xx_rx_skb(struct wcn36xx *wcn, struct sk_buff *skb)

memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));

- hdr = (struct ieee80211_hdr *) skb->data;
- fc = __le16_to_cpu(hdr->frame_control);
- sn = IEEE80211_SEQ_TO_SN(__le16_to_cpu(hdr->seq_ctrl));
-
if (ieee80211_is_beacon(hdr->frame_control)) {
wcn36xx_dbg(WCN36XX_DBG_BEACON, "beacon skb %p len %d fc %04x sn %d\n",
skb, skb->len, fc, sn);
diff --git a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
index 68cc06cf9bc0..35a6590c3ee5 100644
--- a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
+++ b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
@@ -35,6 +35,9 @@
/* How many frames until we start a-mpdu TX session */
#define WCN36XX_AMPDU_START_THRESH 20

+#define WCN36XX_MAX_SCAN_SSIDS 9
+#define WCN36XX_MAX_SCAN_IE_LEN 500
+
extern unsigned int wcn36xx_dbg_mask;

enum wcn36xx_debug_mask {
@@ -212,6 +215,12 @@ struct wcn36xx {
spinlock_t hal_ind_lock;
struct list_head hal_ind_queue;

+ struct work_struct scan_work;
+ struct cfg80211_scan_request *scan_req;
+ int scan_freq;
+ int scan_band;
+ struct mutex scan_lock;
+
/* DXE channels */
struct wcn36xx_dxe_ch dxe_tx_l_ch; /* TX low */
struct wcn36xx_dxe_ch dxe_tx_h_ch; /* TX high */
--
2.5.0

Next message: Bjorn Andersson: "[PATCH v2 1/2] wcn36xx: Transition driver to SMD client"
Previous message: David Miller: "Re: [PATCH net-next V4] net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)"
In reply to: Bjorn Andersson: "[PATCH v2 1/2] wcn36xx: Transition driver to SMD client"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]