Re: [PATCH 1/6] rt2x00: Only initialize HT on rt2800 devices that support it.

[Ivo van Doorn <ivdoorn@gmail.com>]

On Monday 23 November 2009, Gertjan van Wingerde wrote:
> Some RT28xx/RT30xx devices don't support 802.11n, when they are combined with
> the RF2020 chipset. Ensure that HT is disabled for these devices.
> 
> Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
> ---
>  drivers/net/wireless/rt2x00/rt2800lib.c |   59 +++++++++++++++++--------------
>  1 files changed, 32 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
> index e94f1e1..ac393c3 100644
> --- a/drivers/net/wireless/rt2x00/rt2800lib.c
> +++ b/drivers/net/wireless/rt2x00/rt2800lib.c
> @@ -2070,34 +2070,39 @@ int rt2800_probe_hw_mode(struct rt2x00_dev *rt2x00dev)
>  	}
>  
>  	/*
> -	 * Initialize HT information.
> +	 * Initialize HT information, unless when we're on RF2020, which doesn't
> +	 * support 802.11n.
>  	 */
> -	spec->ht.ht_supported = true;
> -	spec->ht.cap =
> -	    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
> -	    IEEE80211_HT_CAP_GRN_FLD |
> -	    IEEE80211_HT_CAP_SGI_20 |
> -	    IEEE80211_HT_CAP_SGI_40 |
> -	    IEEE80211_HT_CAP_TX_STBC |
> -	    IEEE80211_HT_CAP_RX_STBC |
> -	    IEEE80211_HT_CAP_PSMP_SUPPORT;
> -	spec->ht.ampdu_factor = 3;
> -	spec->ht.ampdu_density = 4;
> -	spec->ht.mcs.tx_params =
> -	    IEEE80211_HT_MCS_TX_DEFINED |
> -	    IEEE80211_HT_MCS_TX_RX_DIFF |
> -	    ((rt2x00_get_field16(eeprom, EEPROM_ANTENNA_TXPATH) - 1) <<
> -		IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT);
> -
> -	switch (rt2x00_get_field16(eeprom, EEPROM_ANTENNA_RXPATH)) {
> -	case 3:
> -		spec->ht.mcs.rx_mask[2] = 0xff;
> -	case 2:
> -		spec->ht.mcs.rx_mask[1] = 0xff;
> -	case 1:
> -		spec->ht.mcs.rx_mask[0] = 0xff;
> -		spec->ht.mcs.rx_mask[4] = 0x1; /* MCS32 */
> -		break;
> +	if (!rt2x00_rf(chip, RF2020)) {
> +		spec->ht.ht_supported = true;
> +		spec->ht.cap =
> +			IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
> +			IEEE80211_HT_CAP_GRN_FLD |
> +			IEEE80211_HT_CAP_SGI_20 |
> +			IEEE80211_HT_CAP_SGI_40 |
> +			IEEE80211_HT_CAP_TX_STBC |
> +			IEEE80211_HT_CAP_RX_STBC |
> +			IEEE80211_HT_CAP_PSMP_SUPPORT;
> +		spec->ht.ampdu_factor = 3;
> +		spec->ht.ampdu_density = 4;
> +		spec->ht.mcs.tx_params =
> +			IEEE80211_HT_MCS_TX_DEFINED |
> +			IEEE80211_HT_MCS_TX_RX_DIFF |
> +			((rt2x00_get_field16(eeprom, EEPROM_ANTENNA_TXPATH) - 1) <<
> +				IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT);
> +
> +		switch (rt2x00_get_field16(eeprom, EEPROM_ANTENNA_RXPATH)) {
> +		case 3:
> +			spec->ht.mcs.rx_mask[2] = 0xff;
> +		case 2:
> +			spec->ht.mcs.rx_mask[1] = 0xff;
> +		case 1:
> +			spec->ht.mcs.rx_mask[0] = 0xff;
> +			spec->ht.mcs.rx_mask[4] = 0x1; /* MCS32 */
> +			break;
> +		}
> +	} else {
> +		spec->ht.ht_supported = false;

Isn't it sufficient to only set spec->ht.ht_supported to true or false?
mac80211 should ignore all ht parameters if ht_supported is set to
false anyway (and it saves quite a lot of indenting).

Ivo