On Mon, 2010-04-19 at 12:14 +0200, Felix Fietkau wrote:
> On 2010-04-19 11:09 AM, Johannes Berg wrote:
> > On Mon, 2010-04-19 at 11:06 +0200, Felix Fietkau wrote:
> >> On 2010-04-19 10:59 AM, Johannes Berg wrote:
> >> > On Mon, 2010-04-19 at 10:45 +0200, Felix Fietkau wrote:
> >> >> On 2010-04-19 7:57 AM, Johannes Berg wrote:
> >> >> > On Sun, 2010-04-18 at 18:05 +0200, Felix Fietkau wrote:
> >> >> >
> >> >> >> >> + * @IEEE80211_TX_CTL_STBC: tells the driver to use Space-Time Block Coding
> >> >> >> >> + * (STBC) for this frame.
> >> >> >> >> */
> >> >> >> >> enum mac80211_tx_control_flags {
> >> >> >> >> IEEE80211_TX_CTL_REQ_TX_STATUS = BIT(0),
> >> >> >> >> @@ -299,6 +301,7 @@ enum mac80211_tx_control_flags {
> >> >> >> >> IEEE80211_TX_INTFL_HAS_RADIOTAP = BIT(20),
> >> >> >> >> IEEE80211_TX_INTFL_NL80211_FRAME_TX = BIT(21),
> >> >> >> >> IEEE80211_TX_CTL_LDPC = BIT(22),
> >> >> >> >> + IEEE80211_TX_CTL_STBC = BIT(23),
> >> >> >> >
> >> >> >> > What if the # of streams is different? That doesn't look sufficient.
> >> >> >
> >> >> >> Hm, you're right. I initially thought the combination of the MCS index
> >> >> >> and the STBC flag would be enough, but there are still some corner cases.
> >> >> >
> >> >> > Hm actually I guess that should be sufficient? What corner case are you
> >> >> > thinking of?
> >> >> Support for multi-rate retry and STBC with more than one stream on one
> >> >> side, using rates from both MCS0-7 and MCS8-15 in the rate series.
> >> >> Rx STBC for only one stream on the other side.
> >> >
> >> > So the flag should be per rate entry instead, no?
> >
> >> Well, I think if we use two bits in the tx control flags, we don't need
> >> it to be per rate entry.
> >
> > But then you can't probe stbc properly, can you?
> I'm not sure we even need to probe STBC. In all of the drivers that I've
> looked at, it's always enabled if the peer supports it.
> I'm not aware of any situation where it would make the reception worse,
> aside from hardware damage of course ;)
Ok ... I guess two bits then so you don't have to look up sta capability
when doing the hw programming?
johannes
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