lkml.org 
[lkml]   [2022]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.16 0105/1039] wcn36xx: ensure pairing of init_scan/finish_scan and start_scan/end_scan
    Date
    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 b04533bbc3a45..0747c27f3bd75 100644
    --- a/drivers/net/wireless/ath/wcn36xx/main.c
    +++ b/drivers/net/wireless/ath/wcn36xx/main.c
    @@ -402,6 +402,7 @@ 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);

    @@ -417,17 +418,31 @@ 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);
    }
    @@ -722,7 +737,12 @@ 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 ed45e2cf039be..e44506e4f1d5f 100644
    --- a/drivers/net/wireless/ath/wcn36xx/smd.c
    +++ b/drivers/net/wireless/ath/wcn36xx/smd.c
    @@ -722,6 +722,7 @@ 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;
    @@ -752,6 +753,7 @@ 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;
    @@ -782,6 +784,7 @@ 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;
    @@ -823,6 +826,7 @@ 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;
    --
    2.34.1


    \
     
     \ /
      Last update: 2022-01-25 01:11    [W:4.041 / U:1.592 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site