On 2020-09-16 19:44, Johannes Berg wrote: > On Wed, 2020-09-16 at 18:46 +0200, Felix Fietkau wrote: >> Some APs (e.g. Asus RT-AC88U) have been observed to report an HT MSDU size >> limit of 3839 and a VHT limit of 7991. These APs can handle bigger frames >> than 3839 bytes just fine, so we should remove the VHT limit based on the >> HT capabilities. This improves tx throughput. > > I'm not really convinced that we can do this, since we don't track > HT/VHT limits separately. > > IOW, to be behaving according to the AP you mention, we'd have to know > when building an A-MSDU whether it's going to use HT or VHT rates, but > we don't track that at all ... These comments don't make sense to me. A-MSDU limit is tracked per sta, and on all the implementations I've looked at, HT rates are never used to transmit to a peer that can do VHT. It would be unnecessary to do that anyway, since VHT modulations are a superset of HT modulations with just some header differences. On another note, VHT already supports bigger A-MSDU limits than HT in the code below that check. - Felix
