Re: [PATCH 09/10] carl9170: fw: enable DFS radar detection

[Christian Lamparter <chunkeey@gmail.com>]

On 3/12/26 11:38 AM, Masi Osmani wrote:
> Enable DFS (Dynamic Frequency Selection) radar detection on the
> AR9170.  The hardware has radar detection registers (RADAR_0,
> RADAR_1, RADAR_EXT) and the firmware already sends
> CARL9170_RSP_RADAR events, but the driver never programmed the
> detection parameters and only logged a "please report" message.
> 
> Changes:
> - Program radar detection pulse parameters in phy.c when the
>    current channel has IEEE80211_CHAN_RADAR set.  Values are
>    based on ath9k defaults for FCC/ETSI compliance.

Which values did you use? The best I can find are in ar5008_phy.c
<https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/ath/ath9k/ar5008_phy.c?h=v7.0-rc4#n1268>


|	conf->fir_power = -33;
|	conf->radar_rssi = 20;
|	conf->pulse_height = 10;
|	conf->pulse_rssi = 15;
|	conf->pulse_inband = 15;
|	conf->pulse_maxlen = 255;
|	conf->pulse_inband_step = 12;
|	conf->radar_inband = 8;

the one in the patch look a little bit different.
Can I ask, how did you tune them? Do you have a setup to mimic
those air-port or weather radars? Or are you living close to one?

> - Advertise radar_detect_widths in the interface combination
>    (fw.c) for 20 MHz noHT, 20 MHz HT, and 40 MHz HT.
> - Replace the old "please report" message with a call to
>    ieee80211_radar_detected() so mac80211 can trigger the
>    proper DFS state machine (channel switch / CAC).
> 
> Signed-off-by: Masi Osmani <mas-i@hotmail.de>
> ---
>   drivers/net/wireless/ath/carl9170/fw.c  |  3 ++
>   drivers/net/wireless/ath/carl9170/phy.c | 45 +++++++++++++++++++++++++
>   drivers/net/wireless/ath/carl9170/rx.c  |  7 ++--
>   3 files changed, 50 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/carl9170/fw.c b/drivers/net/wireless/ath/carl9170/fw.c
> index 419f553..a730593 100644
> --- a/drivers/net/wireless/ath/carl9170/fw.c
> +++ b/drivers/net/wireless/ath/carl9170/fw.c
> @@ -215,6 +215,9 @@ static void carl9170_fw_set_if_combinations(struct ar9170 *ar,
>   	ar->if_combs[0].max_interfaces = ar->fw.vif_num;
>   	ar->if_combs[0].limits = ar->if_comb_limits;
>   	ar->if_combs[0].n_limits = ARRAY_SIZE(ar->if_comb_limits);
> +	ar->if_combs[0].radar_detect_widths = BIT(NL80211_CHAN_WIDTH_20_NOHT) |
> +					      BIT(NL80211_CHAN_WIDTH_20) |
> +					      BIT(NL80211_CHAN_WIDTH_40);
>   
>   	ar->hw->wiphy->iface_combinations = ar->if_combs;
>   	ar->hw->wiphy->n_iface_combinations = ARRAY_SIZE(ar->if_combs);
> diff --git a/drivers/net/wireless/ath/carl9170/phy.c b/drivers/net/wireless/ath/carl9170/phy.c
> index bcd9066..c294df7 100644
> --- a/drivers/net/wireless/ath/carl9170/phy.c
> +++ b/drivers/net/wireless/ath/carl9170/phy.c
> @@ -1637,6 +1637,47 @@ void carl9170_update_channel_maxpower(struct ar9170 *ar)
>   	}
>   }
>   
> +static int carl9170_set_radar_detection(struct ar9170 *ar,
> +					struct ieee80211_channel *channel)
> +{
> +	bool enable = channel->flags & IEEE80211_CHAN_RADAR;
> +
> +	carl9170_regwrite_begin(ar);
> +
> +	if (enable) {
> +		/*
> +		 * Configure radar detection pulse parameters.
> +		 * Values based on ath9k's defaults for FCC/ETSI.
> +		 */
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_0,
> +				  AR9170_PHY_RADAR_0_ENA |
> +				  AR9170_PHY_RADAR_0_FFT_ENA |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_0_INBAND, 5) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_0_PRSSI, 1) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_0_HEIGHT, 6) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_0_RRSSI, 12) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_0_FIRPWR, 33));
> +
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_1,
> +				  AR9170_PHY_RADAR_1_MAX_RRSSI |
> +				  AR9170_PHY_RADAR_1_BLOCK_CHECK |
> +				  AR9170_PHY_RADAR_1_RELSTEP_CHECK |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_1_RELSTEP_THRESH, 8) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_1_RELPWR_THRESH, 12) |
> +				  SET_CONSTVAL(AR9170_PHY_RADAR_1_MAXLEN, 255));
> +
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_EXT,
> +				  AR9170_PHY_RADAR_EXT_ENA);


This seems to be based on ar5008_hw_set_radar_params except that:

|	if (conf->ext_channel)
|		REG_SET_BIT(ah, AR_PHY_RADAR_EXT, AR_PHY_RADAR_EXT_ENA);
|	else
|		REG_CLR_BIT(ah, AR_PHY_RADAR_EXT, AR_PHY_RADAR_EXT_ENA);

you always set the EXT_ENA bit?


> +	} else {
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_0, 0);
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_1, 0);
> +		carl9170_regwrite(AR9170_PHY_REG_RADAR_EXT, 0);
> +	}
> +
> +	carl9170_regwrite_finish();
> +	return carl9170_regwrite_result();
> +}
> +
>   int carl9170_get_noisefloor(struct ar9170 *ar)
>   {
>   	static const u32 phy_regs[] = {
> @@ -1739,6 +1780,10 @@ int carl9170_set_channel(struct ar9170 *ar, struct ieee80211_channel *channel,
>   	if (err)
>   		return err;
>   
> +	err = carl9170_set_radar_detection(ar, channel);
> +	if (err)
> +		return err;
> +
>   	tmp = AR9170_PHY_TURBO_FC_SINGLE_HT_LTF1 |
>   	      AR9170_PHY_TURBO_FC_HT_EN;
>   
> diff --git a/drivers/net/wireless/ath/carl9170/rx.c b/drivers/net/wireless/ath/carl9170/rx.c
> index bb909b5..1fe727c 100644
> --- a/drivers/net/wireless/ath/carl9170/rx.c
> +++ b/drivers/net/wireless/ath/carl9170/rx.c
> @@ -259,11 +259,8 @@ void carl9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
>   		break;
>   
>   	case CARL9170_RSP_RADAR:
> -		if (!net_ratelimit())
> -			break;
> -
> -		wiphy_info(ar->hw->wiphy, "FW: RADAR! Please report this "
> -		       "incident to linux-wireless@vger.kernel.org !\n");
> +		wiphy_info(ar->hw->wiphy, "FW: radar pulse detected\n");
> +		ieee80211_radar_detected(ar->hw, NULL);
>   		break;
>   
>   	case CARL9170_RSP_GPIO: