邱名碩 <ccchiu77@xxxxxxxxx> 於 2021年5月10日 週一 下午1:57寫道： > > Hi guys, > I had a problem while verifying the ampdu tx throughput with the > rtl8xxxu driver on RTL8188CUS module. The throughput number is > relatively good, 39~42Mbps TCP on 2.4GHz channel. However, the > retransmission rate is high, it's 15% ~ 21% with rtl8xxxu driver and > It's almost the same result with the rtl8192cu driver. I can get > averagely 7~10% retransmission rate in the same test bed with Realtek > vendor driver. > > From the air capture, I can see the rtl8xxxu driver keep sending > the aggregated frames in MCS7 and doesn't even fall back to lower MCS > index in the subsequent retries. I can only see very few retried > packets been sent with MCS0 or 6Mbps grate. On the vendor driver, I'll > see the retried ampdu packets with MCS4 after 3 retries w/o ack from > the receiver. > > From the rate mask command issued by the h2c command, I force both > the rtl8xxxu driver and vendor driver to use the same ratemask 0xfffff > (MCS 0-7 and b/g rate included) and leave the arg0 as-is (mostly 0xa0) > and I expect both drivers can do the rate adaptive thing in the same > way, but it seems to make no difference. The rtl8xxxu driver still > sends the packets with highest MCS. > > Can anyone tell me what should I expect the rate adaptive to work > with the rate mask 0xfffff and 0xf0000? Does the 0xf0000 means that it > will pick up a tx rate only between nrate MCS4 to MCS7? I need a base > line so that I can judge it's simply a rate mask problem or maybe the > h2c command is not written correctly. Please kindly suggest what I > should do next. Thanks > > Chris
