On 17/03/2025 05:01, Ping-Ke Shih wrote: > Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote: >> >> Tell the chip the maximum AMPDU size supported by the AP. This greatly >> improves the TX speed of RTL8814AU in the 2.4 GHz band. Before: ~90 >> Mbps. After: ~300 Mbps. >> >> Add this configuration for all the chips, even if it only has an effect >> on RTL8814AU in my tests. Surely they all need this. > > The hardware default value of REG_AMPDU_MAX_LENGTH is 0xffff (unlimited) > for most chips. It seems like RTL8812A/RTL8821A are also exceptions, so > at power on function they do > rtw_write32(rtwdev, REG_AMPDU_MAX_LENGTH, 0xffffffff); > > I feel RTL8814A has similar setting, so maybe you can just add similar > stuff. > > By the way, the AMPDU is controlled by TX descriptor basically: > pkt_info->ampdu_factor = ampdu_factor; > pkt_info->ampdu_density = ampdu_density; > pkt_info->ampdu_en = ampdu_en; > > Since you didn't change this part at all, I still feel setting > REG_AMPDU_MAX_LENGTH to 0xffffffff can fix low throughput problem. > I tried 0xffffffff just now and it doesn't work. It's the same with both of my routers. They advertise a maximum AMPDU size of 64 K. I can't just set it to 0xffff either, because then the upload speed in the 5 GHz band suffers a lot. The dual band router advertises a maximum AMPDU size of 256 K in the 5 GHz band so it gets a value of 0x3ffff.
