Re: [PATCH 2/2] wcn36xx: Enable hardware scan offload for 5Ghz band

From: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
To: Loic Poulain <loic.poulain@linaro.org>, kvalo@codeaurora.org
Cc: wcn36xx@lists.infradead.org, linux-wireless@vger.kernel.org
Subject: Re: [PATCH 2/2] wcn36xx: Enable hardware scan offload for 5Ghz band
Date: Mon, 18 Oct 2021 23:51:47 +0100	[thread overview]
Message-ID: <d37b9978-7b0f-69ae-9c2f-693baec8bb2b@linaro.org> (raw)
In-Reply-To: <1634554678-7993-2-git-send-email-loic.poulain@linaro.org>

On 18/10/2021 11:57, Loic Poulain wrote:
> Until now, offload scanning for 5Ghz channels was considered broken.
> However it was mostly a driver issue, caused by bad reporting of the
> beacons/probe-resp bands and frequencies, which has been fixed.
> 
> We can now allow offload scan for 5GHz band, this reduces the scanning
> time comparing to software driven scanning.
> 
> Note that offloaded scan is limited to 48 channels, check for this.
> 
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>   drivers/net/wireless/ath/wcn36xx/main.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
> index 263af65..2ac8efa 100644
> --- a/drivers/net/wireless/ath/wcn36xx/main.c
> +++ b/drivers/net/wireless/ath/wcn36xx/main.c
> @@ -659,19 +659,19 @@ static int wcn36xx_hw_scan(struct ieee80211_hw *hw,
>   			   struct ieee80211_scan_request *hw_req)
>   {
>   	struct wcn36xx *wcn = hw->priv;
> -	int i;
>   
>   	if (!get_feat_caps(wcn->fw_feat_caps, SCAN_OFFLOAD)) {
>   		/* fallback to mac80211 software scan */
>   		return 1;
>   	}
>   
> -	/* For unknown reason, the hardware offloaded scan only works with
> -	 * 2.4Ghz channels, fallback to software scan in other cases.
> +	/* Firmware scan offload is limited to 48 channels, fallback to
> +	 * software driven scanning otherwise.
>   	 */
> -	for (i = 0; i < hw_req->req.n_channels; i++) {
> -		if (hw_req->req.channels[i]->band != NL80211_BAND_2GHZ)
> -			return 1;
> +	if (hw_req->req.n_channels > 48) {
> +		wcn36xx_warn("Offload scan aborted, n_channels=%u",
> +			     hw_req->req.n_channels);
> +		return 1;
>   	}
>   
>   	mutex_lock(&wcn->scan_lock);
> 

Really sweet fix, good job

Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>