From: Benjamin Li benl@squareup.com
[ Upstream commit 8f1ba8b0ee2679f0b3d22d2a5c1bc70c436fd872 ]
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 benl@squareup.com Tested-by: Bryan O'Donoghue bryan.odonoghue@linaro.org Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20211027170306.555535-4-benl@squareup.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5d82aca370a72..cf9e1396bd046 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); } @@ -713,7 +728,12 @@ static void wcn36xx_sw_scan_complete(struct ieee80211_hw *hw, struct wcn36xx *wcn = hw->priv;
/* 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 70bffe3d87a12..6ac770d8271eb 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 e9560f35e9bcf..428546a6047f0 100644 --- a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h +++ b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h @@ -246,6 +246,7 @@ 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;