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From:   Kalle Valo <kvalo@codeaurora.org>
To:     Sven Eckelmann <sven@narfation.org>
Cc:     ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
        Sven Eckelmann <seckelmann@datto.com>,
        Govind Singh <govinds@codeaurora.org>,
        Wen Gong <wgong@codeaurora.org>
Subject: Re: [PATCH v2] ath10k: fix max antenna gain unit
References: <20190611172131.6064-1-sven@narfation.org>
Date:   Tue, 17 Sep 2019 10:28:43 +0300
In-Reply-To: <20190611172131.6064-1-sven@narfation.org> (Sven Eckelmann's
        message of "Tue, 11 Jun 2019 19:21:31 +0200")
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+ Govind, Wen

Sven Eckelmann <sven@narfation.org> writes:

> From: Sven Eckelmann <seckelmann@datto.com>
>
> Most of the txpower for the ath10k firmware is stored as twicepower (0.5 dB
> steps). This isn't the case for max_antenna_gain - which is still expected
> by the firmware as dB.
>
> The firmware is converting it from dB to the internal (twicepower)
> representation when it calculates the limits of a channel. This can be seen
> in tpc_stats when configuring "12" as max_antenna_gain. Instead of the
> expected 12 (6 dB), the tpc_stats shows 24 (12 dB).
>
> Tested on QCA9888 and IPQ4019 with firmware 10.4-3.5.3-00057.
>
> Fixes: 02256930d9b8 ("ath10k: use proper tx power unit")
> Signed-off-by: Sven Eckelmann <seckelmann@datto.com>

[...]

> --- a/drivers/net/wireless/ath/ath10k/mac.c
> +++ b/drivers/net/wireless/ath/ath10k/mac.c
> @@ -1008,7 +1008,7 @@ static int ath10k_monitor_vdev_start(struct ath10k *ar, int vdev_id)
>  	arg.channel.min_power = 0;
>  	arg.channel.max_power = channel->max_power * 2;
>  	arg.channel.max_reg_power = channel->max_reg_power * 2;
> -	arg.channel.max_antenna_gain = channel->max_antenna_gain * 2;
> +	arg.channel.max_antenna_gain = channel->max_antenna_gain;
>  
>  	reinit_completion(&ar->vdev_setup_done);
>  
> @@ -1450,7 +1450,7 @@ static int ath10k_vdev_start_restart(struct ath10k_vif *arvif,
>  	arg.channel.min_power = 0;
>  	arg.channel.max_power = chandef->chan->max_power * 2;
>  	arg.channel.max_reg_power = chandef->chan->max_reg_power * 2;
> -	arg.channel.max_antenna_gain = chandef->chan->max_antenna_gain * 2;
> +	arg.channel.max_antenna_gain = chandef->chan->max_antenna_gain;
>  
>  	if (arvif->vdev_type == WMI_VDEV_TYPE_AP) {
>  		arg.ssid = arvif->u.ap.ssid;
> @@ -3105,7 +3105,7 @@ static int ath10k_update_channel_list(struct ath10k *ar)
>  			ch->min_power = 0;
>  			ch->max_power = channel->max_power * 2;
>  			ch->max_reg_power = channel->max_reg_power * 2;
> -			ch->max_antenna_gain = channel->max_antenna_gain * 2;
> +			ch->max_antenna_gain = channel->max_antenna_gain;
>  			ch->reg_class_id = 0; /* FIXME */

What about firmwares using WMI TLV interface, for example QCA6174 or
WCN3990? Does this break max antenna gain on those devices? Govind, Wen?

-- 
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