Hi all,
I'm trying to make rtl8723bs work with custom A20 board very similar to A20-OLinuXino-MICRO. I made all customization in kernel and wifi seems to work ok, but I have terrible download performance:
iperf3 -c 192.168.0.105 -R -t 30 -i 5
[ ID] Interval Transfer Bandwidth Retr
[ 5] 0.00-32.13 sec 112 MBytes 29.1 Mbits/sec 0 sender
[ 5] 0.00-32.13 sec 111 MBytes 29.0 Mbits/sec receiver
The same configuration have acceptable upload:
iperf3 -c 192.168.0.105 -t 30 -i 5
[ ID] Interval Transfer Bandwidth Retr
[ 5] 0.00-31.98 sec 393 KBytes 101 Kbits/sec 3 sender
[ 5] 0.00-31.98 sec 364 KBytes 93.3 Kbits/sec receiver
iwconfig signal strength:
Link Quality=55/100 Signal level=-67 dBm Noise level=0 dBm
Module is connected using SDC3, since I need video engine support I used `sunxi-3.4` and integrated vendor driver which seems to be similar to rtl8723as.
My system is build using buildroot. I tried to use various profilers but I'm not familiar with those kind of tools to use them like a pro.
Perf show:
26.75% iperf3 [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore
5.64% iperf3 [kernel.kallsyms] [k] sub_preempt_count
5.22% iperf3 [kernel.kallsyms] [k] do_select
5.02% iperf3 [kernel.kallsyms] [k] add_preempt_count
4.83% iperf3 [kernel.kallsyms] [k] ktime_get_ts
Not sure if spending so much time in _raw_spin_unlock_irqrestore is ok. I also tried trace-cmd, but not sure how to interpret results, also had problem with using function plugin - it hangs system.
Anyone faced similar issue ?
Have you got ideas how to debug this problem ?