• Benoit Papillault's avatar
    ath5k: Fix TX/RX padding for all frames · 8127fbdc
    Benoit Papillault authored
    Currently, the padding position is based on
    ieee80211_get_hdrlen_from_skb(). This is not correct since the HW does
    padding on RX (and expect the same padding to be present on TX) at the
    following position :
    
    - management : 24 + 6 if 4-addr format
    - control    : 24 + 6 if 4-addr format
    - data       : 24 + 6 if 4-addr format + 2 if QoS
    - invalid    : 24 + 6 if 4-addr format
    
    whereas ieee80211_get_hdrlen_from_skb() is :
    
    - management : 24
    - control    : 16 except for ACK/CTS where it is 10
    - data       : 24 + 6 if 4-addr format + 2 if QoS + 2 if QoS & order
    - invalid    : 24
    
    So, correct frames are not affected : management frames do not use
    4-addr format, control frames have no body and invalid frames are ...
    not valid by definition. However, in order to use monitor interface for
    debugging purpose, one must be able to send/receive any frames, be it
    correct or not. Such frames are affected by incorrect padding.
    
    Moreover, since padding is added on TX, we need to remove it before
    calling ieee80211_tx_status. This affect TX packets received by monitor
    interfaces.
    
    It has been tested between an ath5k based card (AR5212) and an ar9170usb
    based card (netgear WNDA3100) using a frame generator and a monitor
    interface for each card.
    
    v2: Added ath5k_add_padding / ath5k_remove_padding
    Signed-off-by: default avatarBenoit Papillault <benoit.papillault@free.fr>
    Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
    8127fbdc
desc.c 19.1 KB