[PATCH v2 3/3] wcn36xx: ensure pairing of init_scan/finish_scan and start_scan/end_scan
From: Benjamin Li <hidden>
Date: 2021-10-27 17:03:38
Also in:
linux-arm-msm, lkml, netdev
Subsystem:
atheros ath generic utilities, qualcomm wcn36xx wireless driver, the rest · Maintainers:
Jeff Johnson, Loic Poulain, Linus Torvalds
An SMD capture from the downstream prima driver on WCN3680B shows the
following command sequence for connected scans:
- init_scan_req
- start_scan_req, channel 1
- end_scan_req, channel 1
- start_scan_req, channel 2
- ...
- end_scan_req, channel 3
- finish_scan_req
- init_scan_req
- start_scan_req, channel 4
- ...
- end_scan_req, channel 6
- finish_scan_req
- ...
- end_scan_req, channel 165
- finish_scan_req
Upstream currently never calls wcn36xx_smd_end_scan, and in some cases[1]
still sends finish_scan_req twice in a row or before init_scan_req. A
typical connected scan looks like this:
- init_scan_req
- start_scan_req, channel 1
- finish_scan_req
- init_scan_req
- start_scan_req, channel 2
- ...
- start_scan_req, channel 165
- finish_scan_req
- finish_scan_req
This patch cleans up scanning so that init/finish and start/end are always
paired together and correctly nested.
- init_scan_req
- start_scan_req, channel 1
- end_scan_req, channel 1
- finish_scan_req
- init_scan_req
- start_scan_req, channel 2
- end_scan_req, channel 2
- ...
- start_scan_req, channel 165
- end_scan_req, channel 165
- finish_scan_req
Note that upstream will not do batching of 3 active-probe scans before
returning to the operating channel, and this patch does not change that.
To match downstream in this aspect, adjust IEEE80211_PROBE_DELAY and/or
the 125ms max off-channel time in ieee80211_scan_state_decision.
[1]: commit d195d7aac09b ("wcn36xx: Ensure finish scan is not requested
before start scan") addressed one case of finish_scan_req being sent
without a preceding init_scan_req (the case of the operating channel
coinciding with the first scan channel); two other cases are:
1) if SW scan is started and aborted immediately, without scanning any
channels, we send a finish_scan_req without ever sending init_scan_req,
and
2) as SW scan logic always returns us to the operating channel before
calling wcn36xx_sw_scan_complete, finish_scan_req is always sent twice
at the end of a SW scan
Fixes: 8e84c2582169 ("wcn36xx: mac80211 driver for Qualcomm WCN3660/WCN3680 hardware")
Signed-off-by: Benjamin Li <redacted>
---
drivers/net/wireless/ath/wcn36xx/main.c | 34 +++++++++++++++++-----
drivers/net/wireless/ath/wcn36xx/smd.c | 4 +++
drivers/net/wireless/ath/wcn36xx/wcn36xx.h | 1 +
3 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
index 18383d0fc0933..37b4016f020c9 100644
--- a/drivers/net/wireless/ath/wcn36xx/main.c
+++ b/drivers/net/wireless/ath/wcn36xx/main.c@@ -400,6 +400,7 @@ static void wcn36xx_change_opchannel(struct wcn36xx *wcn, int ch) static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed) { struct wcn36xx *wcn = hw->priv; + int ret; wcn36xx_dbg(WCN36XX_DBG_MAC, "mac config changed 0x%08x\n", changed);
@@ -415,17 +416,31 @@ static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed) * want to receive/transmit regular data packets, then * simply stop the scan session and exit PS mode. */ - wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN, - wcn->sw_scan_vif); - wcn->sw_scan_channel = 0; + if (wcn->sw_scan_channel) + wcn36xx_smd_end_scan(wcn, wcn->sw_scan_channel); + if (wcn->sw_scan_init) { + wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN, + wcn->sw_scan_vif); + } } else if (wcn->sw_scan) { /* A scan is ongoing, do not change the operating * channel, but start a scan session on the channel. */ - wcn36xx_smd_init_scan(wcn, HAL_SYS_MODE_SCAN, - wcn->sw_scan_vif); + if (wcn->sw_scan_channel) + wcn36xx_smd_end_scan(wcn, wcn->sw_scan_channel); + if (!wcn->sw_scan_init) { + /* This can fail if we are unable to notify the + * operating channel. + */ + ret = wcn36xx_smd_init_scan(wcn, + HAL_SYS_MODE_SCAN, + wcn->sw_scan_vif); + if (ret) { + mutex_unlock(&wcn->conf_mutex); + return -EIO; + } + } wcn36xx_smd_start_scan(wcn, ch); - wcn->sw_scan_channel = ch; } else { wcn36xx_change_opchannel(wcn, ch); }
@@ -723,7 +738,12 @@ static void wcn36xx_sw_scan_complete(struct ieee80211_hw *hw, wcn36xx_dbg(WCN36XX_DBG_MAC, "sw_scan_complete"); /* ensure that any scan session is finished */ - wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN, wcn->sw_scan_vif); + if (wcn->sw_scan_channel) + wcn36xx_smd_end_scan(wcn, wcn->sw_scan_channel); + if (wcn->sw_scan_init) { + wcn36xx_smd_finish_scan(wcn, HAL_SYS_MODE_SCAN, + wcn->sw_scan_vif); + } wcn->sw_scan = false; wcn->sw_scan_opchannel = 0; }
diff --git a/drivers/net/wireless/ath/wcn36xx/smd.c b/drivers/net/wireless/ath/wcn36xx/smd.c
index 3cecc8f9c9647..830341be72673 100644
--- a/drivers/net/wireless/ath/wcn36xx/smd.c
+++ b/drivers/net/wireless/ath/wcn36xx/smd.c@@ -721,6 +721,7 @@ int wcn36xx_smd_init_scan(struct wcn36xx *wcn, enum wcn36xx_hal_sys_mode mode, wcn36xx_err("hal_init_scan response failed err=%d\n", ret); goto out; } + wcn->sw_scan_init = true; out: mutex_unlock(&wcn->hal_mutex); return ret;
@@ -751,6 +752,7 @@ int wcn36xx_smd_start_scan(struct wcn36xx *wcn, u8 scan_channel) wcn36xx_err("hal_start_scan response failed err=%d\n", ret); goto out; } + wcn->sw_scan_channel = scan_channel; out: mutex_unlock(&wcn->hal_mutex); return ret;
@@ -781,6 +783,7 @@ int wcn36xx_smd_end_scan(struct wcn36xx *wcn, u8 scan_channel) wcn36xx_err("hal_end_scan response failed err=%d\n", ret); goto out; } + wcn->sw_scan_channel = 0; out: mutex_unlock(&wcn->hal_mutex); return ret;
@@ -822,6 +825,7 @@ int wcn36xx_smd_finish_scan(struct wcn36xx *wcn, wcn36xx_err("hal_finish_scan response failed err=%d\n", ret); goto out; } + wcn->sw_scan_init = false; out: mutex_unlock(&wcn->hal_mutex); return ret;
diff --git a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
index 1c8d918137da2..fbd0558c2c196 100644
--- a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
+++ b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h@@ -248,6 +248,7 @@ struct wcn36xx { struct cfg80211_scan_request *scan_req; bool sw_scan; u8 sw_scan_opchannel; + bool sw_scan_init; u8 sw_scan_channel; struct ieee80211_vif *sw_scan_vif; struct mutex scan_lock;
--
2.25.1