Re: mac80211 and IEEE80211_CONF_SHORT_SLOT_TIME

[Herton Ronaldo Krzesinski <herton@mandriva.com.br>]

On Tuesday 07 October 2008 22:14:12 Herton Ronaldo Krzesinski wrote:
> On Tuesday 07 October 2008 06:05:24 Johannes Berg wrote:
> > Hi,
> >
> > I just realised that for whatever reason mac80211 isn't setting the
> > IEEE80211_CONF_SHORT_SLOT_TIME flag. I'm not sure when or why that was
> > removed, but clearly it isn't used.
> >
> > Can you please fix the drivers using it (b43, b43legacy, iwlwifi, p54,
> > rt2x00, rtl8180, rtl8187) to use the bss_conf's use_short_slot instead?
> > I'll fix mac80211 to set that appropriately.
>
> About 8187 and 8187b, I think the changes below may handle it, I have yet
> to test them, just posting to have some feedback in case there is something
> missing or wrong. I'll try to review the other things too (like
> use_short_preamble warned in the other thread):
>
> diff --git a/drivers/net/wireless/rtl8187_dev.c
> b/drivers/net/wireless/rtl8187_dev.c
> index e990261..7f1cac8 100644
> --- a/drivers/net/wireless/rtl8187_dev.c
> +++ b/drivers/net/wireless/rtl8187_dev.c
> @@ -870,6 +870,32 @@ static void rtl8187_remove_interface(struct
> ieee80211_hw *dev,
>  	mutex_unlock(&priv->conf_mutex);
>  }
>
> +static void rtl8187_conf_slot(struct rtl8187_priv *priv, bool
> use_short_slot) +{
> +	if (priv->is_rtl8187b) {
> +		if (use_short_slot) {
> +			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x9);
> +			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x1c);
> +		} else {
> +			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x14);
> +			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x32);
> +		}
> +		rtl818x_iowrite8(priv, &priv->map->EIFS, 0x5b);
> +	} else {
> +		if (use_short_slot) {
> +			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x9);
> +			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x14);
> +			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x14);
> +			rtl818x_iowrite8(priv, &priv->map->CW_VAL, 0x73);
> +		} else {
> +			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x14);
> +			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x24);
> +			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x24);
> +			rtl818x_iowrite8(priv, &priv->map->CW_VAL, 0xa5);
> +		}
> +	}
> +}
> +
>  static int rtl8187_config(struct ieee80211_hw *dev, struct ieee80211_conf
> *conf)
>  {
>  	struct rtl8187_priv *priv = dev->priv;
> @@ -888,21 +914,8 @@ static int rtl8187_config(struct ieee80211_hw *dev,
> struct ieee80211_conf *conf)
>  	msleep(10);
>  	rtl818x_iowrite32(priv, &priv->map->TX_CONF, reg);
>
> -	if (!priv->is_rtl8187b) {
> -		rtl818x_iowrite8(priv, &priv->map->SIFS, 0x22);
> -
> -		if (conf->flags & IEEE80211_CONF_SHORT_SLOT_TIME) {
> -			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x9);
> -			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x14);
> -			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x14);
> -			rtl818x_iowrite8(priv, &priv->map->CW_VAL, 0x73);
> -		} else {
> -			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x14);
> -			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x24);
> -			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x24);
> -			rtl818x_iowrite8(priv, &priv->map->CW_VAL, 0xa5);
> -		}
> -	}
> +	rtl818x_iowrite8(priv, &priv->map->SIFS, 0x22);
> +	rtl8187_conf_slot(priv, conf->flags & IEEE80211_CONF_SHORT_SLOT_TIME);

grrr, just ignore these two additions that shouldn't be there (I'll move SIFS 
to initialization code or conf_slot functions), and the second line is wrong 
of course.

>
>  	rtl818x_iowrite16(priv, &priv->map->ATIM_WND, 2);
>  	rtl818x_iowrite16(priv, &priv->map->ATIMTR_INTERVAL, 100);
> @@ -938,6 +951,15 @@ static int rtl8187_config_interface(struct
> ieee80211_hw *dev,
>  	return 0;
>  }
>
> +static void rtl8187_bss_info_changed(struct ieee80211_hw *dev,
> +				    struct ieee80211_vif *vif,
> +				    struct ieee80211_bss_conf *info,
> +				    u32 changed)
> +{
> +	if (changed & BSS_CHANGED_ERP_SLOT)
> +		rtl8187_conf_slot(dev->priv, info->use_short_slot);
> +}
> +
>  static void rtl8187_configure_filter(struct ieee80211_hw *dev,
>  				     unsigned int changed_flags,
>  				     unsigned int *total_flags,
> @@ -978,6 +1000,7 @@ static const struct ieee80211_ops rtl8187_ops = {
>  	.remove_interface	= rtl8187_remove_interface,
>  	.config			= rtl8187_config,
>  	.config_interface	= rtl8187_config_interface,
> +	.bss_info_changed	= rtl8187_bss_info_changed,
>  	.configure_filter	= rtl8187_configure_filter,
>  };
>
>
> The values used for SLOT etc. are kept for 8187, for 8187b I got the values
> from realtek GPL driver (nothing is specified in the datasheet).
>
> > johannes

--
[]'s
Herton