On Jan 3, 2008 7:34 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > > We use ieee80211_generic_frame_duration() to compute what we believe > > is the ACK timeout and set it on the rate duration registers, and we > > need this value set during reset, as we up the interface. The *real* > > problem here is we need mac80211 to provide an exported routine which > > drivers can use even if they don't have an up'd interface yet IMHO. > > This can be easily fixed by making ieee80211_generic_frame_duration() > > not rely on sdata and letting the user pass manually if short preamble > > is desired in the calculation as an arg. I have to go now but will try > > to address this as soon as I have time unless someone beats me. > > That'd be wrong as well because w/o a virtual interface you can't be > associated and hence you have no way of knowing whether the frame > duration should be for short preamble or not. Its not because the setting isn't for the targeted currently used rate but instead its for setting the table of duration for the entire list of possible rates for both short *and* for long preamble, whether you are associated or not, on the current mode (a/b/g, custom) you are in. Note that right now we actually ignore short preamble timing and just use long preamble timing but we technically should set both and hence my suggestion. > Besides, the old behaviour was to return 0 from the frame_duration() > function when an invalid interface ID was passed which would always > happen in this function. > > I think you need to rethink what this piece of code is trying to > accomplish and fix it accordingly. You're right. We currently are setting rate duration table upon reset but I believe this is unnecessary as the values *should* remain intact. We really only should be setting the rate duration table upon mode change but: a. I have to take a look at your new mode changes to mac80211 as any effort to change this now may be removed soon anyway b. we still should set the rate duration table depending on the mode One approach we can take here is to just fix ieee80211_frame_duration() to export it for driver use by removing erp stuff and let the routine figure out OFDM erp rates, remove passing ieee80211_local as drivers don't have access to it and move drivers using ieee80211_generic_frame_duration() to this. All this needs some more work and for now we need a quick fix for this oops though as it makes the driver unusable. I'll send a patch based on bruno but does the check in hw reset instead. Luis - 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
