On Mon, Feb 14, 2011 at 11:18:31AM +0100, Johannes Berg wrote: > > > /* Set rssi values to dBm */ > > > hw->flags |= IEEE80211_HW_SIGNAL_DBM; > > > + /* AP FW has rate control */ > > > + if (priv->ap_fw) > > > + hw->flags |= IEEE80211_HW_HAS_RATE_CONTROL; > > > hw->vif_data_size = sizeof(struct mwl8k_vif); > > > hw->sta_data_size = sizeof(struct mwl8k_sta); > > > > I got this same patch (almost exactly the same -- STA firmware actually > > also has rate control so the added AP check in this version of the patch > > is bogus) sent to me a number of times now, the last time from Pradeep > > Nemavat <pnemavat@xxxxxxxxxxx> in private email on Feb 26 2010. This > > is what I wrote back to him at the time: > > > > | mac80211.h says: > > | > > | * @IEEE80211_HW_HAS_RATE_CONTROL: > > | * The hardware or firmware includes rate control, and cannot be > > | * controlled by the stack. As such, no rate control algorithm > > | * should be instantiated, and the TX rate reported to userspace > > | * will be taken from the TX status instead of the rate control > > | * algorithm. > > | * Note that this requires that the driver implement a number of > > | * callbacks so it has the correct information, it needs to have > > | * the @set_rts_threshold callback and must look at the BSS config > > | * @use_cts_prot for G/N protection, @use_short_slot for slot > > | * timing in 2.4 GHz and @use_short_preamble for preambles for > > | * CCK frames. > > | > > | In particular, the "need to report TX rate used in the TX status" > > | requirement is something that we don't do, which is why I didn't merge > > | the IEEE80211_HW_HAS_RATE_CONTROL change upstream yet. (I know that > > | it improves performance, but performance is secondary to correctness.) > > Well, this objection is bogus. If you ask for minstrel rate control, and > then don't use what it does, then not only will it perform less well and > minstrel will converge to some arbitrary value, it will also mean that > the rate reported to userspace (say in tcpdump) is *WRONG*. That's even > worse than not reporting it. Well, OK, but after this patch, it will still report bogus rates to userspace (at least it did when I last tried it). If we're addressing this anyway, let's fix that properly. thanks, Lennert -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
