[PATCH] wcn36xx: Ensure finish scan is not requested before start scan

[Bryan O'Donoghue]

On 18/08/2021 12:31, Loic Poulain wrote:
> From: Joseph Gates <jgates at squareup.com>
> 
> If the operating channel is the first in the scan list, it was seen that
> a finish scan request would be sent before a start scan request was
> sent, causing the firmware to fail all future scans. Track the current
> channel being scanned to avoid requesting the scan finish before it
> starts.
> 
> Cc: <stable at vger.kernel.org>
> Fixes: 5973a2947430 ("wcn36xx: Fix software-driven scan")
> Signed-off-by: Joseph Gates <jgates at squareup.com>
> Signed-off-by: Loic Poulain <loic.poulain at linaro.org>
> ---
>   drivers/net/wireless/ath/wcn36xx/main.c    | 5 ++++-
>   drivers/net/wireless/ath/wcn36xx/wcn36xx.h | 1 +
>   2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
> index dabed4e..e8c772a 100644
> --- a/drivers/net/wireless/ath/wcn36xx/main.c
> +++ b/drivers/net/wireless/ath/wcn36xx/main.c
> @@ -405,13 +405,14 @@ static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed)
>   		wcn36xx_dbg(WCN36XX_DBG_MAC, "wcn36xx_config channel switch=%d\n",
>   			    ch);
>   
> -		if (wcn->sw_scan_opchannel == ch) {
> +		if (wcn->sw_scan_opchannel == ch && wcn->sw_scan_channel) {
>   			/* If channel is the initial operating channel, we may
>   			 * 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;
>   		} else if (wcn->sw_scan) {
>   			/* A scan is ongoing, do not change the operating
>   			 * channel, but start a scan session on the channel.
> @@ -419,6 +420,7 @@ static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed)
>   			wcn36xx_smd_init_scan(wcn, HAL_SYS_MODE_SCAN,
>   					      wcn->sw_scan_vif);
>   			wcn36xx_smd_start_scan(wcn, ch);
> +			wcn->sw_scan_channel = ch;
>   		} else {
>   			wcn36xx_change_opchannel(wcn, ch);
>   		}
> @@ -699,6 +701,7 @@ static void wcn36xx_sw_scan_start(struct ieee80211_hw *hw,
>   
>   	wcn->sw_scan = true;
>   	wcn->sw_scan_vif = vif;
> +	wcn->sw_scan_channel = 0;
>   	if (vif_priv->sta_assoc)
>   		wcn->sw_scan_opchannel = WCN36XX_HW_CHANNEL(wcn);
>   	else
> diff --git a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
> index 71fa999..d0fcce8 100644
> --- a/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
> +++ b/drivers/net/wireless/ath/wcn36xx/wcn36xx.h
> @@ -232,6 +232,7 @@ struct wcn36xx {
>   	struct cfg80211_scan_request *scan_req;
>   	bool			sw_scan;
>   	u8			sw_scan_opchannel;
> +	u8			sw_scan_channel;
>   	struct ieee80211_vif	*sw_scan_vif;
>   	struct mutex		scan_lock;
>   	bool			scan_aborted;
> 

LGTM