Re: [PATCH 1/2] mac80211: Add support of transmit power control (TPC) per data packet

[Johannes Berg <johannes@sipsolutions.net>]

On Fri, 2012-07-27 at 18:00 +0200, Thomas Huehn wrote:

>   * &struct ieee80211_tx_info contains an array of these structs
> - * in the control information, and it will be filled by the rate
> - * control algorithm according to what should be sent. For example,
> - * if this array contains, in the format { <idx>, <count> } the
> + * in the control information, and it will be filled by the joint rate-
> + * power control algorithm according to what should be sent. For example,
> + * if this array contains, in the format { <idx>, <count>, <tpc> } the
>   * information
> - *    { 3, 2 }, { 2, 2 }, { 1, 4 }, { -1, 0 }, { -1, 0 }
> + *    { 3, 2, 16 }, { 2, 2, 10 }, { 1, 4, 5 }, { -1, 0, 0 }
>   * then this means that the frame should be transmitted
> - * up to twice at rate 3, up to twice at rate 2, and up to four
> - * times at rate 1 if it doesn't get acknowledged. Say it gets
> - * acknowledged by the peer after the fifth attempt, the status
> + * up to twice at rate 3 with 16 dBm, up to twice at rate 2 with 10 dBm,

You might want to consider using 1/2 or 1/4 dBm granularity? A lot of
hardware can do that.

>  struct ieee80211_tx_rate {
>  	s8 idx;
>  	u8 count;
>  	u8 flags;
> +	u8 tpc;

I'm not sure that should be named "tpc". Think about what that means --
"transmit power control", but it's really the power value, so it should
be "txpower" or so.

johannes